7-qos b8 print

© Alcatel University - 8AS 90200 1424 VH ZZA Ed.02 .1

© Alcatel University - 8AS 90200 1424 VT ZZA Ed.021.1

Introduction to

QUALITY OF SERVICE and TRAFFIC LOAD

MONITORING

BSS release B8

B8

© Alcatel University - 8AS 90200 1424 VH ZZA Ed.02 Page 1.2

1.2

PROGRAM

1 INTRODUCTION2 GLOBAL INDICATORS3 DETAILED INDICATORS4 HANDOVER INDICATORS5 DIRECTED RETRY INDICATORS6 RADIO MEASUREMENT STATISTICS INDICATORS7 TRAFFIC INDICATORS

B8



1 INTRODUCTION


1.4

1 IntroductionSession presentation

Objective: to be able to explain what is QoS and Traffic Load monitoring of the BSS and what are the information sources available for that purpose

Program: 1.1 Monitoring the QoS of the BSS 1.2 Monitoring the Traffic Load of the BSS1.3 Information sources available1.4 Introduction to K1205 PC emulation



1 INTRODUCTION

1.1 Monitoring the QoS of the BSS


1.6

1.1 Monitoring the QoS of the BSSDefinition

”Monitor" "network" "quality"monitor = measure or ensure? network = BSS? BSS+NSS? BSS+NSS+PSTN …quality = service (end-user) and/or system (technical)

But also detect, localize, diagnose outagesdetect (decide according to thresholds)localize (which cell, BSC, etc.)diagnose: radio, BSS, TC problems


1.7

1.1 Monitoring the QoS of the BSSUsage

QoS ResultsQoS Results

Management•network monitoring•comparison with competitor•comparison of manufacturers•contractual requirement: licence•quality responsible

Management•network monitoring•comparison with competitor•comparison of manufacturers•contractual requirement: licence•quality responsible

Radio optimization•cell radio quality survey•HO quality monitoring•assessment of tuning efficiency

Radio optimization•cell radio quality survey•HO quality monitoring•assessment of tuning efficiency

BSS maintenance•cell/BSC/TC problem detection

BSS maintenance•cell/BSC/TC problem detection

3 usages of QoS data ⇒ 3 levels of QoS reports: 1. Management team: has to compare Network QoS with competitors' one and to plan Network evolutions.

⇒ needs to have a general view of the Network QoS on a monthly (and sometimes weekly) basis.2. Radio Optimization team: has to detect bad QoS areas in the network and to implement and assess modifications for QoSimprovement.

⇒ needs to have a detailed status and evolution of the QoS at BSS and cell (and sometimes TRX) levels on a weekly, daily (and sometimes hourly) basis.

3. Supervision and Maintenance team: has to detect dramatic QoS degradations and identify the responsible Network Element (and if possible component).

⇒ needs to have the most detailed status of QoS at cell and TRX levels on an hourly basis.



1 INTRODUCTION

1.2 Monitoring the Traffic Load of the BSS


1.9

1.2 Monitoring the Traffic Load of the BSS Definition

Measure the "quantity" of traffic handled by:the networkthe BSCsthe cells

Analyze traffic characteristicscall, handover, location update, etc.

As input for dimensioning/architecture team

Traffic characteristics used as a "call mix" to dimension or re-dimension the network will be developed in the section Monitoring the Traffic Load of the BSS.



1 INTRODUCTION

1.3 Information sources available


1.11

1.3 Information sources available Observation means

DIFFERENT WAYS TO OBSERVE/MEASURE the GSM network

External Interface AnalysisA interface: MSC/TC-BSCAbis interface: BSC/BTSAir MS/BTS

Counter browser

OMC CountersBSC(NSS)

Tektronix K1205

Gnnettest MPAW&G NPA

QoS data can be built-up from different and complementary kinds of information sources.Usually post-processing applications will build up QoS indicators from:

OMC-R counters provided by the BSS system itself.Signaling messages provided by a protocol acquisition tool on the different interfaces handled by the BSS: Air, Abis, A (or Ater).

Abis

A

MSC/VLR

AbisBSC TCBTS

Ater

Air

SACCH RSL N7 N7

drive test tool protocol analyzer

MS


1.12

1.3 Information sources available A interface trace

INFORMATION SOURCE: EXTERNAL INTERFACE "A"

Capture/decode signaling between MSC and BSC-TC (A or AterMUX)with "protocol analyzer" (Wandel, Tektronix, Gnnettest, etc.)

+ GSM standard, can be used for arbitrage between manufacturers+ Complete information (message contents, time-stamp)+ Possible detection of User/MS/BSS/TC/NSS problems- High cost of equipment- Time consuming, "post mortem" (installation of tool, file analysis)- Important expertise needed for analysis- Low coverage (K1103/MA10: 8 COCs, K1205/MPA: 32 COCs maximum!) - Large amount of data (>> 10 Mbytes /hour/BSC)

The main advantage of the A interface is to allow the detection of Call Setup failures either due to the User or to the NSS (or PSTN).Some typical user failure causes are: Some typical NSS failure causes are:

IMSI Unknown in VLR Temporary FailureIMSI Unknown in HLR Resource UnavailableIMEI Not Accepted Switching Equipment CongestionPLMN Not Allowed Normal UnspecifiedService Option Not Supported Recovery on Timer ExpiryRequested Service Not Supported Call Reject Unassigned Number InterworkingOperator Determined Barring Protocol ErrorUser Alerting Network FailureFacility Not Subscribed CongestionNo Route to DestinationNormal Call ClearingUser BusyInvalid Number FormatCall RejectInterworkingNormal Unspecified

CAUTION: In order to assess the QoS of a BSS or some cells of a BSS, all N7 links between this BSC and the MSC must be traced. Indeed, as the N7 signaling load is spread over all N7 links, signaling messages relating to one call can be conveyed onany of the active N7 links.

K1103 protocol analyzer can trace up to 8 COCs at the same time but on maximum 4 PCM physical links.K1205 protocol analyzer can trace up to 32 COCs at the same time but on maximum 16 PCM physical links.


1.13

1.3 Information sources available Abis interface trace

INFORMATION SOURCE: EXTERNAL INTERFACE "Abis"Capture/decode signaling between BSC and BTS with "protocol analyzer" (Wandel, Tektronix, Gnnettest, etc.)

Complete information (message contents, time-stamp)Possible detection of User/MS/BSS/TC/NSS problemsComplete radio information thanks to measurement messagesDownlink and uplink

– High cost of equipment– Time consuming, "post mortem" (installation of tool, file analysis)– Important expertise needed for analysis– Very low coverage (A few RSLs, a few cell(s))– Very large amount of data (>> 10 Mbytes/hour/BTS)

The main advantage of the Abis trace is to allow a detailed and precise assessment of the radio quality of a cell at TRX level. Both DownLink and UpLink paths can be observed and compared.BUT from B7 release, the Radio Measurement Statistics (RMS) feature implemented in the BSS provides a good level of information allowing to reduce the number of Abis traces to be done for radio network optimization.


1.14

1.3 Information sources available Air interface trace

INFORMATION SOURCE: EXTERNAL INTERFACE "Air"

Use trace MS to capture signaling and signal characteristics

Give precise location (x,y) of problemsGive downlink radio informationOnly way to localize a lack of coverageOnly way to monitor competitor

– High cost of equipment– Very time-consuming– Difficulty to perform a lot of calls

number of samples insufficient only a few streets

– No uplink

The main advantage of the Air trace is to associate a radio quality measurement to a given geographical area of the network. Even if in release B7 the RMS feature will allow to assess the radio quality as perceived by the end user, no location of the radio problems is provided through the RMS.


1.15

1.3 Information sources available Performance Measurement counters

SUB-SYSTEM COUNTERS

Counts events seen by sub-system, value reported periodically (1 hour)

Low cost: collected directly at OMCCompact data: possibility to store counters for a complete network

– Raw information, having to be consolidated to be understandable– Manufacturer's dependent: questionable/difficult to compare– Weak to analyze other sub-systems

The main advantage of the BSS counters is to provide easily QoS data for permanent QoS monitoring.


1.16

1.3 Information sources available Exercise

Training exerciseDraw the BSS PM counters flow on the chartIn which sub-system are the BSS QoS indicators computed and stored?

BSC

BSC

BSC

OMC-R

OMC-R OMC-R

NPA

NPA is the Alcatel product for the Network Performance Analysis of the Alcatel BSS.RNO is the Alcatel product for the Radio Network Optimization of the Alcatel BSS.


1.17

1.3 Information sources available BSS counters

BSS COUNTERS

Combined into significant formulae: indicatorsUsed to monitor BSS network qualityOver a complete network, with breakdown per cell/BSC

SPECIFIC DRAWBACKNSS/PSTN/MS/USER problems not seen

As BSS PM counters are defined in order to provide information to assess the QoS of the BSS and help to detect BSS misbehavior, there is no way to identify QoS problems due to NSS, PSTN or User.


1.18

1.3 Information sources available NSS counters

NSS COUNTERS

Combined into significant formulas: indicatorsUsed to monitor NSS network qualityOver a complete network, with breakdown per BSC (maximum)

SPECIFIC DRAWBACKSBSS problems usually not precisely identifiedNo breakdown per cell

The NSS QoS is provided through NSS PM counters and indicators. It is out of the scope ot this training course.


1.19

1.3 Information sources available ALCATEL BSS counters

INFORMATION SOURCES: BSS CountersIn order to provide the operators with an easy and cost-effective way to monitor their network and carried traffic, BSS manufacturers have implemented specific software features, called performance management.

The principle is to count for a given duration called granularity period (typically 1 hour) pre-defined events occurring on the Abis or A interface, or internally. These counters are stored for each duration, with breakdown per network component (i.e. cell).

In BSS B8, about 970 counters are available (without GPRS).

In Alcatel BSS (except GPRS), counters are computed by BSC, based mainly on Abis messages.Every reporting period, counters values are sent to the OMC-R for storage.In B7 159 ALCATEL counters are reported to the OMC-R permanently every PM granularity period:

3 per cell adjacency 20 per TRX127 per cell4 per N7 link5 per BSC

⇒ millions of counters are collected every day

Alcatel has chosen to implement PM counters in the BSC and to increment them mostly on Abis interface signaling messages. Other suppliers may have chosen to increment them on A interface signaling messages or to implement them in the BTS. Therefore caution should be taken when interpreting QoS indicators value since some discrepancies may be observed due to these possible choices.


1.20

1.3 Information sources available Example of BSS counter

MC718: counter numberNB_TCH_NOR_ASS_SUCC_TRX: counter nameCumulative: method of computationType 110: Overview measurements: BSS PM measurement type to which the counter belongs Measured object: minimum object level for which the counter is provided: TRX or CELL or BSC or N7 LINK or X25 LINK etc.

Counter Example

All counters are described in the "PM counters and indicators" document whose B7 reference is xxxxxxxxx.


1.21

1.3 Information sources available BSS counter characteristics

Collection mechanism

CumulativeThe counter is incremented at the occurence of a specific eventAbis or A message, or internal eventAt the end of a collection period, the result is the sum of the events

InspectionEvery 20 or 10 seconds, a task quantifies an internal resource status (usually a table)At the end of a collection period, the result is the mean value

ObservationSet of recorded information about a telecom procedure (handover,channel release, UL & DL measurements reporting)

Main counters are of cumulative type. Inspection counters are of gauge type.Observation counters are grouped in a Performance Measurement record associated to a particular GSM BSS telecom procedure: SDCCH channel seizure, TCH channel seizure, internal handover, etc.


1.22

BSS Performance Measurement types

1.3 Information sources available BSS PM types

N° Type Name Type definition1 Traffic Measurement Set of counters related to the traffic evaluation per telecom procedure2 Resource Availability Measurement Set of counters related to the availability of the CCCH, SDCCH, or TCH channels3 CCCH channel resource usage measurements Set of counters related to the usage of CCCH channel (PCH, AGCH, RACH)4 SDCCH channel resource usage measurements Set of counters related to the usage of SDCCH channel5 TCH channel resource usage measurements Set of counters related to the usage of TCH channel6 TCH Handover Measurements Set of counters related to the TCH handover procedure7 LAPD Measurement Set of counters related to the LapD logical links8 X.25 Measurement Set of counters related to the X25 links OMC-BSC9 N7 Measurement Set of counters related to the N7 Signaling Links

10 SDCCH Observations Observation counters on SDCCH channels allocated11 TCH measurements observations Observation counters on 08.58 MEASUREMENT REPORT for a TCH12 Internal Handover Observations Observation counters on internal intra-cell or inter-cell SDCCH or TCH handover13 Incoming External Handover Observations Observation counters on incoming external SDCCH or TCH handover14 Outgoing External Handover Observations Observation counters on outgoing external SDCCH or TCH handover15 TCH Observation Observation counters on TCH channel allocated18 A Interface measurements different causes of 08.08 CLEAR REQUEST and 08.08 ASSIGNMENT FAILURE19 SMS PP Measurements Set of counters related to Short Message Service Point to Point25 SCCP Measurements Set of counters related to SCCP Layer of the N7 signaling Links26 TCH outgoing Handover per adjency Set of counters related to outgoing TCH handover provided per adjency27 TCH incoming Handover per adjency Set of counters related to incoming TCH handover provided per adjency28 SDCCH Handover Set of counter related to the SDCCH handover procedure29 Directed Retry measurements Set of counter related to the directed retry handover procedure30 SMS CB Measurements Set of counters related to Short Message Service Cell Broadcast31 Radio Measurement Statistics Set of counters providing radio quality measurements for TRX/Cell32 Change of frequency band measurements Set of counters related to handovers including a change of TCH Frequency band

110 Overview measurements Set of key counters allowing to access Quality of Service of a given Cell/BSC/Network180 Traffic Flow measurements Set of counters related to incoming inter-cell SDCCH/TCH handover performed

per (servin a cell, target cell) adjency

B8

NewB8

BSS Performance Measurement types (PM types) are split into two categories: standard types (7, 8, 9, 18, 19, 25, 28, 29, 30, 31, 32,110, 180)detailed types (1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 26, 27)

The most important types for QoS monitoring and Radio Network Optimization are in bold.A standard PM type can be activated for the whole network. It means that the related counters are reported for all the Network Elements they are implemented on (TRX, CELL, N7 link, X25 link, LAPD link, Adjacency).A detailed PM type can be activated only on a sub-set of the network. It means that the related counters are reported only for a limited number of Network Elements:

40 cells per BSS for PM types 1, 2, 3, 4, 5, 6, 26, 2915 cells per BSS for PM types 10, 12, 13, 14, 151 cell per BSS for PM types 11, 27

Counter numbering rules: Cyz: cumulative or inspection counters in PM types 1, 2, 3, 4, 5, 6, 18, 19, 25, 26, 27, 28, 29, 30, 32, 180Ly.z: cumulative counters in PM type 7 (L stands for LAPD link)Xy.z: cumulative counters in PM type 8 (X stands for X25 link)Ny.z: cumulative counters in PM type 9 (N stands for N7 link)Syz: observation counters in PM type 10 (S stands for SDCCH)Ryz:: observation counters in PM type 11 (R stands for Radio measurements)HOyz: observation counters in PM type 12, 13, 14 (HO stands for HandOver)Tyz: observation counters in PM type 15 (T stands for TCH)RMSyz: cumulative counters in PM type 31 (RMS stands for Radio Measurement Statistics)MCyz or MNy.z: cumulative counters in PM type 110 (M stands for Major)


1.23

1.3 Information sources available Observation means

Training exercise: find the best source of information

Observation to be done : best source why

overall radio quality of 1 cell Counters Type 31 : RMS

monitor user failures

get average network quality

localise precise location of a radio pb

identify abnormal cells in a network

history of network quality for several weeks

compare networks quality

discriminate problems between BSS/NSS. BSSand NSS coming from different providersmake statistics about complete network

In a building, one is thinking that an elevator isinducing PCM trouble, how to confirm ?Identify potential interfering cells of 1 cell



2 GLOBAL INDICATORS


1.25

2 Global indicatorsSession presentation

Objective: to be able to explain what is a Global indicator and what are the main BSS indicators regarding GSM services provided by the Alcatel BSS

Program: 2.1 Indicators definition2.2 Methodological precautions2.3 Typical call failures2.4 Description of global indicators2.5 Traps and restrictions of global indicators2.6 Global indicators interpretation



2 GLOBAL INDICATORS

2.1 Indicators definition


1.27

2.1 Indicators definitionGlobal / detailed

BSS INDICATORS DEFINITION (Alcatel)

Numerical data providing information about network performance regarding:

The complete network: GLOBAL indicatorAn element of the network: DETAILED indicator

TS/TRX/CELL/BTS/BSC/TCA formulae of several counter(s)Counters vs. Indicators

Counters: provided by the BSS equipmentsIndicators: computed by BSS Monitoring equipments

The indicators computation can be performed from several counters or by a simple counter mapping.Example:

call drop rate = Call Drop nb / Call nb = f(counters)call drop = Call drop nb = 1 counter


1.28

2.1 Indicators definitionGlobal

GLOBAL INDICATORS

Measure the performance of the complete network

Analyzed according their trend and valuesUsually every day (week, month)

Compared with:Competitor results if availableContractual requirementsInternal quality requirements


1.29

2.1 Indicators definitionThresholds

EXAMPLE: Thresholds on Call Drop Rate indicator

Weekly CDR "GSM"

0,00%

0,50%

1,00%

1,50%

2,00%

2,50%

3,00%

3,50%

1 5 9 13 17 21 25 29 33 37 41 45

week number

CD

R

weekly call drop ratecontractual call drop ratequality CDR

Weekly CDR "GSM"

0,00%

0,50%

1,00%

1,50%

2,00%

2,50%

3,00%

3,50%

1 5 9 13 17 21 25 29 33 37 41 45

week number

CD

R

weekly call drop ratecontractual call drop ratequality CDR

The Call Drop rate at network level has to compared to: Contractual threshold: can be requested by the operator management to the operational radio team, can be requested by the operator to the provider on swap or network installationQuality threshold: fixed internally by radio team management.

Quality thresholds are usually more tight than contractual ones.


1.30

2.1 Indicators definitionExercise

TRAINING EXERCISE: GLOBAL OR NOT

INDICATOR DESCRIPTION G ?average of call setup success rate for the network Yesrate of call lost due to radio pb on cell CI=14, LAC=234 Nocall drop rate in your capitalcall drop rate of the cell covering a specific buidling% of HO with the cause better cell (among other causes) for the networkaverage rate of TCHs dropped for all TRXs of the network carrying 1 SDCCH8rate of SDCCHs dropped on TRX1 of cell 12,24call success of 1 PLMN% of cells being congested today



2 GLOBAL INDICATORS

2.2 Methodological precautions


1.32

2.2 Methodological precautions Objective

METHODOLOGICAL PRECAUTIONS

Avoid typical errors regarding indicators interpretation


1.33

A good value for a global indicator

⇓All network components are OK regarding this indicator

ExampleA global call drop rate of 1%Can hide some cells with 10 % of call drop rate

2.2 Methodological precautions Global indicator value


1.34

2.2 Methodological precautions Network Element aggregation

THE AVERAGE VALUE OF AN INDICATOR FOR A NETWORKIS NOT THE AVERAGE OF CELL RESULTS (or any sub-part of it)BUT THE AVERAGE WEIGHTED BY THE TRAFFIC

number of calls number of call drop call drop ratecell 1 390 8 2,10%cell 2 546 29 5,25%cell 3 637 20 3,10%cell 4 1029 12 1,14%cell 5 536 3 0,50%cell 6 2 1 50,00%cell 7 3 1 33,00%cell 8 210 4 2,11%cell 9 432 5 1,20%cell 10 321 4 1,11%

average of cell results 9,95%total nb of drop/total number of calls 2,10%


1.35

2.2 Methodological precautions Time period aggregation

Take care of data consolidation

Example: Mean cell congestion rate during busy hourWeighted average of cell congestion at the busy hour of the network? Weighted average of cell congestion rate for its specific busy hour? (definition of busy hour?)

Usually: Cell Busy Hour = hour of the day where max TCH traffic (in erlang) is observed.BSC Busy Hour = hour of the day where max TCH traffic (as the sum of the TCH traffic of all cells of the BSS) is observed.


1.36

2.2 Methodological precautions Exercise

METHODOLOGICAL PRECAUTION: Training exercise

INDICATOR Sample(calls)

conclusion OK ?

call drop = 0.9% in your country 2456435 all the cells have a good call drop NOK

call setup success for cell 15, 145 = 99,5% 2315 there is a good call setup success rate for15,145

In Paris : 2500 cells with 95% of call setupsuccessIn the rest of France : 5000 cells with98%

3267872for France

In France, call setup success = 97 %

call drop for BSS « BSS_1 » = 1% 4500 the call drop for BSS_1 is good

call drop for cell 156;13 = 5% 215 cell 156;13 has certainly a trouble

for BSS 1, call drop of 2,0%for BSS 2, call drop of 3,0%

40002000

LA = BSS1 + BSS2 has a call drop of 2,3 %

MSC « Stadium » has a call setup success of95 %

15346 BSS1 belonging to MSC Stadium has a call setupsuccess of 95¨%



2 GLOBAL INDICATORS

2.3 Typical call failures


1.38

2.3 Typical call failures Objective

Description of the main call success and failures cases, withMain specific countersMain protocol timers

Diagnose the main case of failures on A interface traces using K1205 emulation software


1.39

2.3 Typical call failures Call Setup phasing

4 stages for a call establishment, 2 for a location updateRadio link establishment"SDCCH phase"then only for "Circuit Switch call"TCH assignment "Alerting/connection" phase

Each phase has a specific utility and weaknesses


1.40

2.3 Typical call failures Radio Link Establishment - OC success

Originated Call: RLE success case

T3101: guard timer for SDCCH allocation (Default: 3 seconds)CR/CC are used to exchange SCCP references

Any further message related to this call will have one (or 2) of these 2 referencesK1205 can extract the call using these references (SLR, DLR!!)

MS BTS BSC MSC

CHANNEL REQUEST-------------(RACH)------------> CHANNEL REQUIRED

----------------------------------------------> MC8CCHANNEL ACTIVATION (SDCCH)

<---------------------------------------------- MC148CHANNEL ACTIVATION ACK

---------------------------------------------->IMMEDIATE ASSIGN COMMAND

IMMEDIATE ASSIGN <---------------------------------------------- start T3101MC8B

<------------(AGCH)-------------SABM (L3 info)

-------------(SDCCH)-----------> ESTABLISH IND (L3 info)UA (L3 info) ----------------------------------------------> stop T3101

<-----------(SDCCH)------------- MC02CR (COMPLETE L3 INFO)---------------------------------->

CC<----------------------------------

B8

NewB8

Specific case of Call establishmentfailure:

Loss of messages due to LapD congestioncan be follow with a new counter (see notes)LapD

The SDCCH resource allocation is performed by the BSC. Once allocated the SDCCH channel is activated by the BTS on BSC request.T3101 is the guard timer for the SDCCH access from the MS. The Default value is 3 seconds. MC8C counts the number of Channels Required received from the MS in a cell.MC148 counts the number of SDCCH channels activated (therefore allocated) in a cell.MC8B counts the number of time an MS is commanded to access an SDCCH channel in a cell.MC02 counts the number of MSs which have successfully accessed an SDCCH in a cell as part of a Mobile Originating (MO) call.

The SCCP Connection Request message is conveyed on an A interface PCM timeslot chosen by the BSC (called COC).The SCCP Connection Confirm message is conveyed on a COC chosen by the MSC which can be located on a different PCM than the one of the COC used by the BSC to send signaling messages to the MSC.

Take care than, when the BSC is congested on the downlink, some messages are discarded. This may result for example in call establishment failures, loss of paging messages or delay in handover procedures.

From B8A new LapD counter that indicates the time a LapD link is congested is created to analyze the cause of a degraded quality of service. This counter is implemented in type 7 and thus only be available in a detailed measurement campaign.

Counter: L1.18: TIME_LAPD_CONGDefinition: Time in seconds during which the LapD link is congested in transmission in the BSC.


1.41

2.3 Typical call failures Radio Link Establishment - TC success

Terminated Call: RLE success caseMS BTS BSC MSC

PAGINGPAGING COMMAND <----------------------------------

PAGING REQUEST <---------------------------------------------- start T3113<-------------(PCH)-------------- MC8A


----------------------------------------------> MC8CCHANNEL ACTIVATION (SDCCH)

<---------------------------------------------- MC148CHANNEL ACTIVATION ACK

---------------------------------------------->IMMEDIATE ASSIGN COMMAND

IMMEDIATE ASSIGN <---------------------------------------------- Start T3101<------------(AGCH)------------- MC8B

SABM (PAGING RESP)-------------(SDCCH)-----------> ESTABLISH IND (PAGING RESP)

UA (PAGING RESP) ----------------------------------------------> Stop T3101<-----------(SDCCH)------------- MC01

CR (COMPLETE L3 INFO)---------------------------------->

stop T3113CC

<----------------------------------

A paging message is broadcast by the MSC to all BSCs controlling cells belonging to the same Location Area as the one of the paged MS.In case no MS is accessing the SDCCH channel (T3101 expiry) then the BSC does not repeat the Immediate Assignment since the MS may have accessed an SDCCH in another BSS. It is up to the MSC to repeat Paging if T3113 expires (usually around 7 seconds).MC8A counts the number of Paging Command messages sent on a cell.MC01 counts the number of MSs which have successfully accessed an SDCCH in a cell as part of a Mobile Terminating (MT) call.

Caution: A paging Request message sent on the Air interface by the BTS may contain several MS identities. 3 Paging Request types can be used: in Paging Request Type 1: up to 2 MSs (IMSI1,IMSI2) can be included.in Paging Request Type 2: up to 3 MSs (IMSI1,TMSI1,TMSI2) can be included. in Paging Request Type 3: up to 4 MSs (TMSI1,TMSI2,TMSI3,TMSI4) can be included.

On the other hand, a Paging message and a Paging Command message relate to only one MS identity.


1.42

2.3 Typical call failures Radio Link Establishment - Paging

RLE > PagingMC8A=C8A

Normally all cells of the same Location Area must have the same MC8A counter value since all these cells must be paged for an MT call on an MS located in the Location Area they are included in.If not: it means that a cell is not declared in the right LA at NSS level.


1.43

2.3 Typical call failures Radio Link Establishment - RACH counter

RLE > RACHMC8C=C8C

Caution: All Channels Required (therefore RACH) are counted in MC8C: valid and invalid causes (see later). Indeed ghost RACHsare also counted.The Channel Required content corresponds to the Channel Request message sent by the MS to the BTS.This Channel Request message is made up of one byte with 2 Informations Elements (IEs):

8 7 6 5 4 3 2 1 +-----------------------------------------------+│ ESTABLISHMENT │ RANDOM ││ + - - - - - - - - + ││ CAUSE │ REFERENCE │+-----------------------------------------------+

ESTABLISHMENT CAUSEThis information field indicates the reason for requesting the establishment of a connection. This field has a variable length (from 3 bits up to 6 bits).RANDOM REFERENCEThis is an unformatted field with a variable length (from 5 bits down to 2 bits).

Due to the fact that the NECI bit is always set to 1 in Alcatel BSS, Establishment causes can be divided into 2 categories: Valid causes: 5 (6 if GPRS)000: Location Update (Normal, Periodic, IMSI Attach)100: Terminating call101: Emergency call 110: Call Re-establishment111: Originating call (not emergency)011: if GPRS is implemented in the cell

Invalid causes: 3 (2 if GPRS)001: 010: 011: if GPRS is not implemented in the cell


1.44

2.3 Typical call failures Radio Link Establishment - OC success counters split

RLE > success MO splitMC02x=C02x

MC02 = MC02A+MC02B+MC02C+…….+MC02G+MC02H+MC02i

MC02A: LU

MC02B: SMS

MC02C: SS

MC02D: LU follow-on

MC02E: CR

MC02F: unknown

MC02G: IMSI Detach

MC02H: EC or NC

MC02i: LCS

B8

NewB8

MC02A = Number of SDCCHs successfully seized for Normal or Periodic LU request (IMSI Attach also counted).MC02B = Number of SDCCHs successfully seized for Short Message Service.MC02C = Number of SDCCHs successfully seized for Supplementary Service.MC02D = Number of SDCCHs successfully seized for LU with follow-on bit set to 1 (means that the SDCCH phase will be followed by a TCH assignment for speech call establishment).MC02E = Number of SDCCHs successfully seized for Call Re-establishment.MC02F = Number of SDCCHs successfully seized in case of L3 Info (within 08.58 ESTABLISH INDICATION) unknown by the BSC but transferred to the MSC.MC02G = Number of SDCCHs successfully seized for IMSI Detach.MC02H = Number of SDCCHs successfully seized for Normal or Emergency call.MC02i = Number of Mobile Originating SDCCH establishments for LCS purpose.

Also, Evaluation of The Mobiles location (see the next slides)

LCS: Location Services

B8


1.45

2.3 Typical call failures LCS

LCS function (linked to MC02i) and other counters …LCS allows to access the MS location provided by the BSS.

On MS request to know its own location (MC02 impacted, see the previous slide)On network request (especially during Emergency calls)On external request (LCS Client)

Positioning methods provided can be:

Cell-ID or Cell-ID + TA (Timing Advance)Conventional (standalone) GPSAssisted GPS (with the help of A-GPS server to compute location)

MS based (MB): MS is able to perform a pre computation

MS assisted (MA): MS sends info, Network computes

B8

Assisted GPS Method:

Mobile-based: The MS performs OTD signal measurements and computes its own location estimate. In this case the network provides the MS with the additional information such as BTS coordinates and the RTD values. These assistance data can be either broadcast on the CBCH (using SMSCB function) or provided by the BSS in a point to point connection (either spontaneously or on request from the MS).Mobile-assisted: The MS performs and reports OTD signal measurements to the network and the network computes the MS location estimate.With

OTD: Observed Time Difference: the time interval that is observed by an MS between the receptions of signals (bursts) from two different BTSs.RTD: Real Time Difference: This means the relative synchronization difference in the network between two BTSs.

Finally, 4 methods are possible for positioning:Cell ID+ TAConventional (MS equipped with GPS System)A-GPS MS BasedA-GPS MS Assisted

These 4 Methods induce a set of counters (2 per method) to give the average latitude and longitude of mobiles in the cell.These counters are located in the MFS and can be used in RNO (cartographic part).


1.46

2.3 Typical call failures LCS

LCS function: Architecture

B8

SMLCBTS

BTS

MS

BSC

MSC

HLR

GMLC

OSP

Lg

Lh

ExternalLCS client

LeA

Abis

Abis

Lb

SMLC function integrated in MFS:

- receives the loc. Request from the GMLC through the MSC/BSC

- Schedules all the necessary actions to get MS location

- Computes MS location

- Provides the result back to the GMLC

MFSA-GPS server

SAGI

GPS reference network

LCS: Location ServicesSMLC: Serving Mobile Location CenterGMLC: Gateway Mobile Location CenterA-GPS: Assisted GPS

Where is my son?

Where am I?

Where is the accident? Emergency call

MS Request

Network Request

External Request

2

1

3

3

2

1

In case of MS requests for its location, MC02 is impacted: MC02i = Number of Mobile Originating SDCCH establishments for LCS purpose.

In all cases, some counters related to LCS provide specific information (attempts, success, failures)see the next slide.


1.47

2.3 Typical call failures Radio Link Establishment - SDCCH congestion failure

SDCCH ACCESS FAILURE

SDCCH congestionSDCCH congestion

SDCCH RF access failureSDCCH RF access failure

SDCCH access failure BSS pbSDCCH access failure BSS pb

Main failure cases for Radio Link Establishment


1.48

2.3 Typical call failures Radio Link Establishment - SDCCH congestion

RLE > SDCCH congestion

The Immediate Assignment Reject mechanism can be disabled at OMC-R levelAnd is not activated for answer to paging If disabled, no answer to the MS

The MS will repeat automatically its request in case of congestion (next slides)Waiting for T3122 expiry in case of Immediate Assignment RejectWaiting for T3120 expiry otherwise

MS BTS BSCMSC


----------------------------------------------> MC8CNo free SDCCH !!MC04

IMMEDIATE ASSIGN COMMAND<----------------------------------------------

IMM. ASS. REJECT (immediate assignment reject) MC8D, and MC8B<-------------(AGCH)------------

In case of Immediate Assignment Reject: T3122 = value of Wait_Indication parameter sent by the BSC to the MS.

Otherwise T3120 is computed by the MS as a random number of slots between:

250 and 250+T-1 for a phase 1 MS where: T=Tx_integer parameter (1 value per cell chosen between 3 to 50 slots)

S and T+S for a phase 2 MS where: T=Tx_integer parameter (1 value per cell chosen between 3 to 50 slots)S is a parameter depending on the CCCH configuration and on the value of Tx_integer as defined in the following table:

TX_integer S(CCCH Not Comb) S(CCCH Combined)

3, 8, 14, 50 55 414, 9, 16 76 525, 10, 20 109 586, 11, 25 163 867, 12, 32 217 115


1.49

2.3 Typical call failures Radio Link Establishment - SDCCH congestion counter

RLE > SDCCH congestionMC04=C04


1.50

2.3 Typical call failures Radio Link Establishment - SDCCH cong. consequence

RLE > SDCCH congestionMAIN CONSEQUENCES

The MS will try "max_retrans +1 " time before giving upImmediately for phase 1 MSAfter T3126 for phase 2 MS (still waiting for Immediate Assignment during this timer)

In case of "max_retrans+1" failures, the MS willEither try an automatic cell reselectionOr do nothing

In case of LU, the MS will attempt a new LU requestIn case of Call establishment, the MS will not re-attempt automatically, it is up to the subscriber to try to set up the call again


1.51

2.3 Typical call failures Radio Link Establishment - SDCCH cong. causes


MAIN CAUSES

Too much SDCCH "normal" traffic for cell SDCCH designRadio resource capacity not sufficient (too many calls)Inadequate LA design (too many LUs)

"Common Transport Effect"Difficult to avoid for small cells

Abnormal SDCCH traffic”Phantom" channel requests (seen in SDCCH RF failure session)Neighboring cell barred

SDCCH congestion can be too high because of the subscribers' traffic demand in terms of calls / LU.Solution = add a TRX or site / redesign the LA plan

High SDCCH congestion can be observed at peculiar period of the day due to a peak of LU requests generated by a big group of subscribers entering a new LA at the same time (bus, train, plane).

Solution = redesign the LA plan or play on radio parameters (CELL_RESELECT_HYSTERESIS, WI_OP)

High SDCCH congestion can be abnormally observed without real MS traffic in case a high level of noise or the proximity of a non-GSM radio transmitter.

Solution = change the BCCH frequency or put an RX filter

High SDCCH congestion can also be abnormally observed in a cell in case one of its neighboring cell is barred.Solution = Remove the barring


1.52

2.3 Typical call failures Radio Link Establishment - SDCCH cong. Resolution?


DYNAMIC SDCCH ALLOCATION

Defining too many SDCCHs will lead to a lack of TCH resources... and money. Defining too few SDCCH channels will result in SDCCH congestion. TCH channels cannot be allocated and, once again, the operator 's revenue decreases. At OMC-R level, it is possible to configure:

a set of static SDCCH/x timeslots to handle normal SDCCH traffic;a set of dynamic SDCCH/8 timeslots, which can be used for TCH traffic, or for SDCCH traffic depending on the need.

With the "Dynamic SDCCH allocation" feature, the BSS is automatically looking after varying SDCCH traffic and is particularly adapted to the situations such as: change of LA, change of SMS traffic model, SDCCH traffic varying due to LCS.This feature is particularly useful in very dense (hierarchical) networks, where the effort to optimize the SDCCH configuration becomes more important.

B8

This feature not only improves SDCCH congestion but also successful TCH assignment rates.


1.53

2.3 Typical call failures Radio Link Establishment - SDCCH cong. Resolution?


DYNAMIC SDCCH ALLOCATION

B8

CHANNEL REQUESTCHANNEL REQUIRED

MS BTS BSC

(RACH)

If No free SDCCH, thenrun dynamic SDCCH/8 timeslot allocationalgorithm. If allocation is successful, then

activate dynamic SDCCH sub-channel and serve request

If allocation was unsuccessful, then reject SDCCH request (possiblyusing the Immediate Assignment Reject procedure).

MC801a&b

MC802a&b

SPECIFIC COUNTERS (Type 110 / Cell Level): MC800 Average number of available dynamic SDCCH/8 timeslots. MC801a Average number of busy dynamic SDCCH/8 timeslots allocated as TCH (FR or HR).MC801b Maximum number of busy dynamic SDCCH/8 timeslots allocated as TCH (FR or HR). MC802a Average number of busy SDCCH sub-channels allocated on the dynamic SDCCH/8 timeslots. MC802b Maximum number of busy SDCCH sub-channels allocated on the dynamic SDCCH/8 timeslots.

These four previous counters are”Inspection Counters” ; that means than the resource is checked regulary by the BSC and at the end of the period, an average is done. Example: 3 physical chanels are defined as Dyn SDCCH and the counter give the following indication:MC801a = 1.7 that means sometimes the 3 Dyn SD are allocated as TCH, sometimes only 2 of them, sometimes 1 or 0 and the average is 1.7

The FOLLOWING COUNTERS ARE IMPACTED BY the Dynamic SDCCH Allocation feature: MC28, MC29 The Number of busy radio timeslots in TCH usage takes into account the busy TCH timeslots and the dynamic SDCCH/8 timeslots allocated as TCH.C30, MC31 The Number of busy SDCCH sub-channels takes into account the SDCCH sub-channels allocated on the static and dynamic SDCCH/8 timeslots.C370a, MC370a, C370b, MC370b The Number of times the radio timeslots are allocated for TCH usage (FR / HR) takes into account the busy TCH timeslots and the dynamic SDCCH/8 timeslots allocated as TCH.C/MC380a/b C/MC381a/b The Cumulated time (in second) the radio timeslots are allocated for TCH usage (FR or HR)does not take care whether the TCHs are allocated on the TCH radio timeslot or on the dynamic SDCCH/8 timeslots. C39, MC390, C40, MC400 The Number of times or the Cumulated time (in second) the SDCCH sub-channels are busydoes not take care whether the SDCCH sub-channels are allocated on the static or dynamic SDCCH/x timeslot.C/MC34 C/MC380 The Cumulated time (in second) all TCHs / SDCCHs in the cell are busydoes not take care whether the TCHs / SDCCHs are allocated on the TCH radio timeslot /SDCCH/x timeslot or on the dynamic SDCCH/8 timeslots.C/MC320a/b/c/d/e Free TCH radio timeslotscount the free TCH timeslots and the free dynamic SDCCH/8 timeslots.


1.54

2.3 Typical call failures Radio Link Establishment - SDCCH radio failure

TYPICAL CALL FAILURES







1.55

2.3 Typical call failures Radio Link Establishment - SDCCH radio access failure

RLE > SDCCH RF Failure

MS BTS BSC MSCCHANNEL REQUEST

-------------(RACH)------------> CHANNEL REQUIRED----------------------------------------------> MC8C

CHANNEL ACTIVATION (SDCCH)<---------------------------------------------- MC148

CHANNEL ACTIVATION ACK---------------------------------------------->IMMEDIATE ASSIGN COMMAND

IMMEDIATE ASSIGN <---------------------------------------------- start T3101<------------(AGCH)------------- MC8B

IMMEDIATE ASSIGN-------(SDCCH)-----X

T3101expiry->“radio failure”MC149

MC149 counts the number of SDCCH access failures due to radio problems.


1.56

2.3 Typical call failures Radio Link Establishment - real radio problems


Main causes > real radio problems

Unbalanced cell power budgetBad coverage (for example a moving car)Interference (for example downlink)

In case of radio failure, the MS will retry as for SDCCH congestion

Unbalanced Power Budget:

Bad coverage:

Interference:

DL interference area

AGCH lost

RACH

building

BTS

Channel Request

Access Grant

Max Path Loss ULMax Path Loss DL

AGCH

RACH


1.57

2.3 Typical call failures Radio Link Establishment - Ghost RACH (1/7)


Main causes > "Phantom/Ghost/Spurious/Dummy ... RACH"

Channel request received but not sent: 3 causesNoise decodingReception of channel request sent to a neighboring cellReception of HO_ACCESS sent to a neighboring cell


1.58

2.3 Typical call failures Radio Link Establishment - Ghost RACH (2/7)


Main causes > "Phantom/Ghost/Spurious/Dummy ... RACH"Example of a channel required message

For this Channel Required, the establishment cause is valid (Call re-establishment) but the Access Delay (corresponding to the distance between the MS and the BTS) is high.Indeed the Access Delay being equal to the Timing Advance is coded in slot unit representing a distance of 550m. It can take values from 0 (0m) to 63 (35km).Thus the Channel Required above is received from an MS located at 19km from the site. It may therefore be rather a ghost RACH than a real MS which wants re-establish a call.In Alcatel BSS, there is possibility to filter the Channel Required received from a distance greater than a distance defined as a parameter value: RACH_TA_FILTER tunable on a per cell basis. Caution should be taken since a too low value may reduce the network coverage.


1.59

2.3 Typical call failures Radio Link Establishment - Ghost RACH causes (3/7)


Main causes > "Phantom RACH" >noise decoding

GSM 05.05: " 0.02 % of Rach Frame can be decoded without error without real input signal"

BCCH not combined: 51 Rach/Multi Frame > (3600 * 1000) ms / 4.615 ms at 0.02 %: 156 dummy RACH/hourBCCH combined: 27/51 RACH/Multi-Frame > 83 dummy RACH/hour3/8 of causes (field of channel request, 5 valid causes over 8) will be unvalidExample of induced SDCCH traffic: (5/8*156*T3101 (3 sec))/3600 = 0.08 Erlang SDCCH

This extra-load has no impact for the system

Some tips: Dummy Rach load depends on minimum level for decoding configured in Evolium BTSDuring period with low real traffic (night), high rate of dummy RACHFor dummy RACH, the channel required has a random value of TA

STRUCTURE of the MULTIFRAME in "TIME SLOT" 0

-

R = RACH DOWNLINK

f s b b b b C C C C31 51 1211 2 3 4 5 6 7 8 9 10 20 41

f s f s f s f sC C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C -

(Multiframes of 51 frames)

f = FCCH s = SCH b = BCCH

f s

C C C C = CCCH (PCH or AGCH)

UPLINKR R R RR R R R R R R RR R R R R R R RR R R R R R R RR R R R R R R RR R R RR R R RR R R R R R

(Non-combined BCCH)

(Combined BCCH)

R = RACH

DOWNLINK

F = FCCH S = SCH B = BCCH C = CCCH (PCH or AGCH)

UPLINK

F S B C F S F S F S -F SC C D0 D1 D2 D3 A0 A1

F S B C F S F S F S -F SC C D0 D1 D2 D3 A2 A3

R R R RR R R R R R R RR R R R R R RR R R R R RR RD3 A2 A3 D0 D1 D2

R R R RR R R R R R R RR R R R R R RR R R R R RR RD3 A0 A1 D0 D1 D2

Dn/An = SDCCH/SACCH/4

51 multiframe duration = 51 x 8 x 0,577 = 235ms


1.60



Main causes > "Phantom RACH" >noise decoding

No subscriber -> no impact for subscriberBut MC149 incremented -> SDCCH RF access failure is impacted

MS BTS BSC MSC

CHANNEL REQUIRED----------------------------------------------> MC8C



IMMEDIATE ASSIGN <---------------------------------------------- start T3101<------------ (AGCH) ------------- MC8B

T3101expiry->“radio failureMC149


1.61



Main causes > "Phantom RACH" > Channel Request sent to the neighboring cell

Subscriber not impacted (real transaction performed elsewhere)

But MC149 incremented -> SDCCH RF access failure is impacted

Usual radio planning rules are sufficient to avoid the trouble

2 cells must not have same (BCCH, BSIC) couple

M S B T S B S C M S C

C H A N N E L R E Q U IR E D--- -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -> M C 8 C

C H A N N E L A C T IV A T IO N (S D C C H )< --- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M C 1 4 8

C H A N N E L A C T IV A T IO N A C K--- -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ->

IM M E D IA T E A S S IG N C O M M A N DIM M E D IA T E A S S IG N < --- -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - s ta r t T 3 1 0 1 M C 8 B

< ---- - - - - - - - - (A G C H )--- - - - - - - - - - -

T 3 1 0 1 e x p iry M C 1 4 9-> “ra d io fa ilu re

BSIC = BCC (3 bit) + NCC (3 bit)BCC: BTS Color Code NCC: Network Color Code


1.62



Main causes > "Phantom RACH" > Channel Request due to handover

During HO, the first message sent to the target cell is HO AccessThis message is an Access Burst like Channel Request

If received on BCCH, can be understood as a Channel Request (RACH)A new case of "Phantom RACH"


1.63



Main causes > "Phantom RACH" > Channel Request due to handover

This case is the most dangerousThe MS sends usually a sequence of HO Access message, every frameIn some cases, this can create a phantom RACH if

The frequency of the TCH is identical or adjacent to the one of interfered BCCH

Characteristics of such phantom RACH (Channel Required)Subsequent frame numberRandom, but stable timing advance

Can block very easily SDCCH


1.64

2.3 Typical call failures Radio Link Establishment - BSS failure

TYPICAL CALL FAILURES







1.65

2.3 Typical call failures Radio Link Establishment - BSS problem

RLE > BSS problem

No specific counter

MS BTS BSC MSCCHANNEL REQUEST

-------------(RACH)------------> CHANNEL REQUIRED----------------------------------------------> MC8C



IMMEDIATE ASSIGN <---------------------------------------------- start T3101<------------(AGCH)------------- MC8B

SABM (L3 info)------------(SDCCH)------------>

BSS Problems are difficult to specify a priori. It is better to deduce them from other counters which are easier to implement thus more reliable.


1.66

RLE counters

2.3 Typical call failures Radio Link Establishment - counters

Request MC8C

GPRS causes P62CGSM invalid causes unknown

Preparation GSM valid causes unknown

Congestion MC04BSS Pb unknown

Execution Attempt MC148

Radio Access Failure MC149BSS Pb MC148 - (MC01+MC02) - MC149

Success MC01+MC02

Radio Link Establishment

REQUEST

Congestion

ATTEMPT

Radio access failure

SUCCESS

BSS problem

Preparation Failure

Execution Failure

GPRS causes GSM/GPRS invalid causes GSM valid causes

BSS problem

Statistically a ghost RACH can correspond to any kind of establishment cause: valid and invalid.As ghost RACH which corresponds to a GSM valid cause will lead to an SDCCH allocation which will not be seized by an MS, it will lead to the incrementation of MC149 counter and therefore counted as an SDCCH access failure due to radio.


1.67

2.3 Typical call failures Radio Link Establishment - indicators

TYPICAL CALL FAILURES: RLE indicators

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS: GLOBAL Quality of service INDICATORS > SDCCH > Assignment Phase

SDNAUR: SDCCH assignment unsuccess rateSDNACGR: SDCCH assignment failure rate due to congestion (Global)SDNAFLRR: SDCCH assignment failure rate due to radioSDNAFLBR: SDCCH assignment failure rate due to BSS problem

A SDCCH radio access failure due to ghost RACH occurrence is easily observed during low traffic hour (night time) since ghost RACHs are almost the only cause of failure.


1.68

2.3 Typical call failures SDCCH phase - OC success

Successful SDCCH phase: OC call

transparent message: no dedicated counters

MS BTS BSC MSCSDCCH Phase : Originating Call case

< -------------------------------------------------------------------------------------------------------------------------AUTHENTICATION REQUEST

------------------------------------------------------------------------------------------------------------------------- >AUTHENTICATION RESPONSE

< -------------------------------------------------------------------------------------------------------------------------CIPHERING MODE COMMAND

------------------------------------------------------------------------------------------------------------------------- >CIPHERING MODE COMPLETE

------------------------------------------------------------------------------------------------------------------------- >SETUP

< -------------------------------------------------------------------------------------------------------------------------CALL PROCEEDING

Transparent messages (DTAP) are used in order the NSS performs control procedures to enable the MS to set up a speech call.Authentication: Checks that the Mobile Station is the required station and not an intruder.Ciphering: All Information (signaling, Speech and Data) is sent in cipher mode, to avoid monitoring and intruders (who could analyze signaling data).Setup/Call Processing: call is being processed between the calling Party and the Called Party.


1.69

2.3 Typical call failures SDCCH phase - TC success

Successful SDCCH phase: TC call


MS BTS BSC MSCSDCCH Phase : Terminating Call case





< -------------------------------------------------------------------------------------------------------------------------SETUP

------------------------------------------------------------------------------------------------------------------------- >CALL CONFIRM

Setup/Call Confirm: the call is being processed between the Calling Party and the Called Party.


1.70

2.3 Typical call failures SDCCH phase - LU success

successful SDCCH phase: Location Update


MS BTS BSC MSCSDCCH Phase : Location Update Case (with TMSI reallocation)

------------------------------------------------------------------------------------------------------------------------- >LOCATION UPDATE REQUEST





< -------------------------------------------------------------------------------------------------------------------------LOCATION UPDATE ACCEPT

------------------------------------------------------------------------------------------------------------------------- > TMSI REALLOCATION COMPLETE

Some transparent messages are also exchanged between the MS and the network in case of a Location Update transaction.


1.71

2.3 Typical call failures SDCCH phase - drops

SDCCH phase

Loss of connection during SDCCH phase = "SDCCH drop"

3 origins of SDCCH dropRadio problems when connected on SDCCHBSS problemsCall lost during an SDCCH HO (handover failure without reversion to old channel)

Generally SDCCH handover are disabled in the network since the average SDCCH duration is only around 2 to 3 seconds.


1.72

2.3 Typical call failures SDCCH phase - radio drop

SDCCH phase > drop radio

Connection lost due to radio problem

MS BTS BSC MSCSDCCH Phase established

Radio connection lost---------------------------------------------------- > MC138CONNECTION FAILURE INDICATION

(cause : radio link failure)--------------------------------------- >CLEAR REQUEST

Cause : radio interface failure

MC138 counts the number of SDCCH channel drops due to radio problems.Radio problems can be due to coverage, interference and sometimes BSS dysfunction which is not detected as a system alarm the by O&M Fault Management application.


1.73

2.3 Typical call failures SDCCH phase - BSS drop

SDCCH phase > drop BSS

Connection lost due BSS problem


MC137

--------------------------------------- >CLEAR REQUEST

Cause : O&M interventionCause : radio interface failure

MC137 counts the number of SDCCH channel drops due to BSS problems.A BSS problem can be a BTS/BSC hardware or software failure. It can also be due to a problem on the Abis interface (due to Micro Wave transmission for instance).


1.74

SDCCH phase > drop HO

Connection lost during HandOver


HO FAILURE WITHOUT REVERSION MC07--------------------------------------- >

CLEAR REQUESTRadio Interface Message Failure (Alcatel)

2.3 Typical call failures SDCCH phase - HO drop

MC07 counts the number of SDCCH channel drops due to handover failure.


1.75

SDCCH phase counters

2.3 Typical call failures SDCCH phase - counters

SDCCH connection MC01+MC02+MC10

SDCCH Drop Drop radio MC138Drop BSS MC137Drop HO MC07

SDCCH Phase

TCH assignment phase SDCCH drop

SDCCH connection

Normal release

Drop radio

Drop BSS

Drop HO


1.76

2.3 Typical call failures SDCCH phase - indicators

SDCCH phase indicators

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS > SDCCH > Established phase

SDCDR: SDCCH drop rate (Global)SDCDRR: SDCCH drop rate due to radio problemSDCDBR: SDCCH drop rate due to BSS ProblemSDCDHR: SDCCH drop rate due to HO failure


1.77

2.3 Typical call failures TCH assignment - success

TCH assignment success case

T3107: guard timer for TCH assignment

MS BTS BSC MSCTCH ASSIGNMENT PHASE (OC or TC)

< -----------------------------------ASSIGNMENT REQUEST

< --------------------------------------------------------PHYSICAL CONTEXT REQUEST

-------------------------------------------------------- >PHYSICAL CONTEXT CONFIRM

< -------------------------------------------------------- MC703CHANNEL ACTIVATION (TCH)

-------------------------------------------------------- >CHANNEL ACTIVATION ACKNOWLEDGE

< ----------------------------------------------------------------------------------- Start T3107 (SDCCH) ASSIGNMENT COMMAND

---------------------- >TCH SABM -------------------------------------------------------- >

< ---------------------- ESTABLISH INDICATIONUA

----------------------------------------------------------------------------------- > Stop T3107ASSIGNMENT COMPLETE MC718

----------------------------------- >ASSIGNMENT COMPLETE

MC140a

MC140b

B8

MC460a New B8

MC140a

MC140b

MC460a

(see comments)

MC703 counts the number of TCH channels activated (therefore allocated) in a cell.MC718 counts the number of MSs which have successfully accessed a TCH in a cell as part of a call establishment (Normal Assignment).Both counters are new from B7 since they are now implemented at TRX level.

MC140a counts the number of normal assignment requests for TCH establishment.MC140b counts the number of normal assignment commands for TCH establishment.Both counters are new in B8 in order to discriminate BSS problems in Preparation and Execution phases.

MC460a is a new counter in B8 for type 110: NB_TCH_EMERGENCY_HO_PRESERVATION: Definition: Number of high priority TCH requests served when:

the number of free TCH timeslots is less than or equal to NUM_TCH_EGNCY_HO.the queue for this cell is not empty.

MC140a, MC140b and MC460 are given at Cell level


1.78

TCH assignment > congestion

5 causes of congestion ⇒ 5 counters: C612A, B, C, D, E whenever

Queuing is not allowedQueue is FullT11 expiresRTCH request is removed from the queue due to a higher priority request to be queuedNo Abis-TCH resource is available (Restriction in B8)


< -----------------------------------------------ASSIGNMENT REQUEST

No RTCH available on requested cell MC812

------------------------------------------------ >ASSIGNMENT FAILURE

Cause No Radio Resource Available

2.3 Typical call failures TCH assignment - TCH congestionB8 (See comments)

New counter in B8: C612E: Number of 08.08 ASSIGNMENT REQUEST for TCH normal assignment rejected due to congestion on the Abis interface.Therefore B6 counter MC612 is replaced by MC812 from B7. MC812 = C612A+C612B+C612C+C612D+C612E of PM Type 1.But as C612E is in restriction in B8 (always = 0) then MC812(B7) = MC612(B6)MC612A, MC612B, MC612C, MC612D also exist in PM Type 110.A TCH request is attached a Priority Level from 1 (highest priority) to 14 (lowest priority).


1.79

TCH assignment > radio failure

Radio problemMS BTS BSC MSC

TCH ASSIGNMENT PHASE (OC or TC)< -----------------------------------ASSIGNMENT REQUEST






SABM----(TCH)------X

T3107 ExpiryMC746B----------------------------------- >

ASSIGNMENT FAILURERadio interface failure

2.3 Typical call failures TCH assignment - radio failure

MC140a

MC140b

MC746B counts the number of TCH access failures due to radio problems.MC746B counter is implemented at TRX level from B7.In case of TCH access failure, the MS will try to revert back to the SDCCH channel. Whether it succeeds in reverting to the SDCCH or not the call establishment fails. On the other hand some MSCs may resend the ASSIGNMENT REQUEST again.


1.80

TCH assignment > BSS problem

BSS problem (Abis, BTS/BSC HW or SW)

2.3 Typical call failures TCH assignment - BSS problem








SABM----(TCH)---- >

MC14B

MC140a

MC140b

No specific counter

B8

The number of TCH Assignment failures due to BSS Pb can be correctly deduced and distinguished for preparation and execution phases from B8 with the 2 new counters MC140a and MC140b.(see the next slide)


1.81

TCH assignment counters

2.3 Typical call failures TCH assignment - counters

Congestion

ATTEMPT

Radio access failure

SUCCESS

BSS problem

Preparation Failure

Execution Failure

REQUEST

BSS problemTCH Assignment

Preparation Request MC140a

Congestion MC812

BSS Pb MC140a-MC140b-MC812

Execution Attempt MC140b

Radio Access Failure MC746b

BSS Pb MC140b-MC718-MC746b

Success MC718

B8

NewB8

BSS PB

discrimination


1.82

TCH Assignment indicators

2.3 Typical call failures TCH assignment - indicators

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS > RTCH > Assignment Phase

TCNAUR: TCH assignment unsuccess rate (Global)TCNACGR: TCH assignment failure rate due to congestionTCNAFLRR: TCH assignment failure rate due to radio problemsTCNAFLBR: TCH assignment failure rate due to BSS Problems.

From B7.2 some indicators can be provided on a per TRX basis due to the availability of new counters provided per TRX in Type 110:

TCNAEFR = RTCH_assign_efficiency_rate (RNO name) = MC718 / MC703Rate of successful RTCH seizures in relation to all RTCHs allocated, during the TCH assignment procedure.

TCNAAFLRR = RTCH_assign_allocated_fail_radio_rate (RNO name) = MC746B / MC703Rate of RTCH seizures failed during the normal assignment procedure because of radio problems in relation to all RTCHs allocated for TCH assignment procedure.

This will help a lot to detect bad QOS due to TRX hardware related problem.


1.83

TCH phase

Transparent messages for BSS, no specific countersTCH DROP: any problems occurring after TCH assignment (during or after connection) cannot be discriminated

MS BTS BSC MSCAlerting Connection Phase (OC case) : ringing phase

< ---------------------------------------------------------------------------------------------------------------------------ALERTING

< ---------------------------------------------------------------------------------------------------------------------------CONNECT

--------------------------------------------------------------------------------------------------------------------------- >CONNECT ACK

MS BTS BSC MSCAlerting Connection Phase : TC case

--------------------------------------------------------------------------------------------------------------------------- >ALERTING

--------------------------------------------------------------------------------------------------------------------------- >CONNECT

< ---------------------------------------------------------------------------------------------------------------------------CONNECT ACK

2.3 Typical call failures TCH phase - success





< --------------------------------------------------------CHANNEL ACTIVATION (TCH)



---------------------- >TCH SABM -------------------------------------------------------- >

< ---------------------- ESTABLISH INDICATIONUA

----------------------------------------------------------------------------------- > Stop T3107ASSIGNMENT COMPLETE

----------------------------------- >ASSIGNMENT COMPLETE

< ---------------------------------------------------------------------------------------------------------------------------ALERTING

< ---------------------------------------------------------------------------------------------------------------------------CONNECT

---------------------------------------------------------------------------------------------------------------------------->CONNECT ACK

Call Setup

Call phase

Call Setup

Call phase

The Call setup phase and the Stable call phase are not corresponding between the BSS and the NSS. For the BSS, a call is established when the MS has successfully accessed a TCH channel on the Air interface. For the NSS, a call is established when the speech data exchanged is started between end users.Thus the Call setup phase is shorter and the Call phase is longer in the BSS.Therefore Call Setup Success rate is worse in the NSS and the Call Drop rate is worse in the BSS.


1.84

TCH phase > drop radio

Radio problem

MS BTS BSC MSCAlerting Connection Phase or Communication : at any time

Radio problem-------------------------------------------------------- > MC736

CONNECTION FAILURE INDICATION --------------------------------------- >Cause radio link failure CLEAR REQUEST

Cause radio interface failure(alcatel)

2.3 Typical call failures TCH phase - radio drop

MC736 counts the number of TCH channel drops due to radio problems.MC736 counter is implemented at TRX level from B7.Radio problems can be due to coverage, interference and sometimes BSS dysfunction which is not detected as a system alarm by the O&M Fault Management application.


1.85

TCH phase > drop TC

Remote TransCoder problem


Radio problem-------------------------------------------------------- > MC739

CONNECTION FAILURE INDICATION --------------------------------------- >Remote transcoder failure CLEAR REQUEST

Equipment failure

2.3 Typical call failures TCH phase - remote TC drop

MC739 counts the number of TCH channel drops due to BSS problems reported as "remote TransCoder failure".MC739 counter is implemented at TRX level from B7.It can usually be a bad quality of the transmission on the Abis interface (Micro Wave) or a faulty hardware component in the TransCoder or even sometimes BSS software/hardware problems.


1.86

TCH phase > drop BSS internal

Other internal BSS problem (excluding TC)


MC14C--------------------------------------- >

CLEAR REQUESTO&M intervention

Radio interface failure

2.3 Typical call failures TCH phase - BSS internal drop

MC14C counts the number of TCH channel drops due to BSS problems other than the ones reported by the TransCoder.A BSS problem can be a BTS/BSC hardware or software failure.


1.87

TCH phase > drop HO

Handover failure


HO FAILURE WITHOUT REVERSION MC621--------------------------------------- >

CLEAR REQUESTRadio Interface Message Failure (Alcatel)

2.3 Typical call failures TCH phase - HO drop

MC621 counts the number of TCH channel drops due to Handover failure.MC621 counter is implemented at TRX level from B7.This event is also counted in the set of Handover counters as an Outgoing handover failure without reversion to the old channel.


1.88

TCH phase > drop preemption

TCH preempted

MS BTS BSC MSCAlerting Connection Phase of a call

with priority level pl2 and preemption vulnerability indicator pvi=1no TCH free

ASSIGNMENT REQUEST<---------------------------------------

Priority level pl1 > pl2preemption capability indicator pci=1

MC921C--------------------------------------- >

CLEAR REQUESTpreemption

2.3 Typical call failures TCH phase - preemption drop

MC921C counts the number of TCH channel drops due to preemption for another call to be established.MC921C counter exists from B7 as linked to the feature Preemption.


1.89

TYPICAL CALL FAILURES: TCH phase counters

2.3 Typical call failures TCH phase - counters

TCH connection MC718+MC717A+MC717B

Outgoing HO success MC712

Call drop Drop radio MC736Drop TC MC739Drop internal BSS MC14CDrop HO MC621Drop preemption MC921C

Normal release unknownNSS abnormal release unknown

TCH Phase

Outgoing HO success Call drop

TCH connection

Normal release

Call drop radio

Call drop BSS

Call drop HO

Call drop preemption

TC

BSS internal

NSS abnormal release


1.90

TYPICAL CALL FAILURES: TCH phase indicators

Call drop rate = call drop / RTCH success end

RTCH success end = RTCH assignment success + RTCH incoming (HO+DR) success - RTCH outgoing HO

2.3 Typical call failures TCH phase - call drop rate

Incoming internal HO+DR

BSS1 BSS2

Incoming external HO+DR

outgoing HO

TCH assignment

QSCDN = call drop = drop radio + drop TC + drop internal BSS + drop HO + drop Preemption= MC736 + MC739 + MC14C + MC621 + MC921C

TCQHCCN = RTCH success end = assignment success + incoming (HO+DR) success - outgoing HO= MC718 + (MC717A+MC717B) - MC712

As MC718, MC717A, MC717B and MC712 are provided per TRX, the “RTCH success end” indicator (TCAHCCN) can be computed per TRX.But since only MC736 (drop radio), MC739 (drop TC) and MC621 (drop HO) are provided per TRX, the “call drop rate” indicator (QSCDR) can be computed per CELL only.On the other hand the following call drop indicators can be computed per TRX:

call drop radio rate (QSCDRR) = call drop radio / RTCH success endcall drop HO rate (QSCDHR) = call drop HO / RTCH success end call drop TC rate (QSCDBTR) = call drop TC / RTCH success end

Note: MC718 counts the number of successful TCH assignments.MC717A counts the number of successful internal DRs.MC717B counts the number of successful incoming internal and external (HOs+DR) as well as the number of intra cell HOs successfully performed.MC712 counts the number of successful outgoing internal and external HOs as well as the number of intra cell HOssuccessfully performed.


1.91


RTCH drop rate = call drop / RTCH success begin

RTCH success begin = RTCH assignment success+ RTCH incoming (HO+DR) success- RTCH intra cell HO success

2.3 Typical call failures TCH phase - RTCH drop rate

BSS1 BSS2


TCH assignment

Incoming external HO+DR

outgoing HO

Intra-cell HO


TCQHSUBN = RTCH success begin = assignment success + incoming (HO+DR) success - intra cell HO= MC718 + (MC717A+MC717B) - MC662

As MC662 is not provided per TRX, the “RTCH success begin” indicator (TCAHSUBN) cannot be computed per TRX but per CELL only.Therefore all “RTCH drop rate” indicators can be computed per CELL only.

Note: MC662 counts the number of successful TCH intracell HOs.


1.92


TRX TCH drop rate = call drop / RTCH success

RTCH success = RTCH assignment success+ RTCH incoming (HO+DR) success

2.3 Typical call failures TCH phase - TRX TCH drop rate


TCH assignment

outgoing HOBSS1 BSS2

Incoming external HO+DRIntra-cell HO


TCAHSUN = RTCH success = assignment success + incoming (HO+DR) success= MC718 + (MC717A+MC717B)

Whereas some call drop rate indicators are defined per TRX and per CELL, TRX RTCH drop rate indicators are defined at TRX level only.As MC718, MC717A, MC717B are provided per TRX, the “RTCH success” indicator (TCAHSUN) can be computed per TRX.But since only MC736 (drop radio), MC739 (drop TC) and MC621 (drop HO) are provided per TRX, a global“TRX RTCH drop rate”indicator cannot be provided.On the other hand, the following TRX RTCH drop indicators can be computed:

TRX_RTCH_drop_radio_rate (TCAHCDRTR) = call drop radio / RTCH successTRX_RTCH_drop_HO_rate (TCHOCDTR) = call drop HO / RTCH successTRX_RTCH_drop_BSS_remote_TC_rate (TCTRTCDTR) = call drop TC / RTCH success

CAUTION: Intra-cell HO being counted in MC717B and not deduced in the RTCH success computation in order to provide the TRX RTCH drop indicators at TRX level then these indicators may be abnormally low (good) if a large amount of intra-cell HOs are performed in the cell (concentric cell, multiband cell).


Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8:

call drop indicators: all of them are available per CELL only and some of them per TRX

GLOBAL Quality of service INDICATORS > Call Statistics > Call dropQSCDR: call drop rate (Global): CELLQSCDRR: call drop rate due to radio: CELL + TRXQSCDBIR: call drop rate due to BSS internal problem: CELLQSCDBTR: call drop rate due to TransCoder reported problem: CELL + TRXQSCDHR: call drop rate due to HO failure: CELL + TRXQSCDPR: call drop rate due to preemption: CELL

RTCH drop indicators: all of them are available per CELL only

GLOBAL Quality of service INDICATORS > RTCH > Established phaseQSTCCDR: RTCH drop rateTCAHCDRR: RTCH drop rate due to radio problemTCTRICDBR: RTCH drop rate due to BSS internal problemTCTRTCDR: RTCH drop rate due to TransCoder reported problemTCHOCDR: RTCH drop rate due to HO failureTCPPCDR: RTCH drop rate due to preemption

TRX TCH drop indicators: all of them are available per TRX only

GLOBAL Quality of service INDICATORS > RTCH > Established phaseTCAHCDRTR: TRX TCH drop rate due to radio problemTCTRTCDTR: TRX TCH drop rate due to TransCoder reported problemTCHOCDTR: TRX TCH drop rate due to HO failure


1.94

TYPICAL CALL FAILURES: summary

call stage A interface cause field related problem

radio linkestablishment

no message - - SDCCH congestionradio problem- dummy rach

SDCCH phase Clear Request - radio interface failureradio interface failure- O&M intervention

- radio problem- BSS system HW/SW pb- recovery/operator

TCH assignment Assignment Failure - no radio resource avalaible- Radio Interface Failure

- TCH congestion- Radio problem

Alerting/connectioncall established

Clear Request - radio interface failureradio interface message failure- equipment failure- O&M interventionradio interface failure-preemption

- radio problem- HO failure w/o reversion- Transcoder failure- operator action/recovery- BSS system HW/SW pb- preemption

2.3 Typical call failures summaryB8 (See comments)

NewB8 New LAPD counter to analyze the cause of call establishment failures

When the BSC is congested on the downlink, some messages are discarded. This may result for example in call establishment failures, loss of paging messages or delay in handover procedures.

A new LapD counter that indicates the time a LapD link is congested is created to analyze the cause of a degraded quality of service. This counter is implemented in type 7 and thus is only available in a detailed measurement campaign.


B8



2 GLOBAL INDICATORS

2.4 Description of global indicators


1.96

2.4 Description of global indicatorsrecall

Global Indicators areA set of indicators selected by Alcatel Useful to monitor the overall network

What are the user and or system impacts if a GI is bad?


1.97

SDCCH CONGESTION rate: may have impact for subscriberCall setup failure only after 3 subsequent congestionsIf not, only some extra delay for call establishment

(less than 1 second) without immediate_assign_rejectCan be longer with reject (but usually short values are used for call request)

2.4 Description of global indicatorsSDCCH congestion rate

INDICATOR(G)

SDCCH ASSIGN CONG FAIL RATE

DEFINITION Rate of SDCCH not allocated during radio link establishment procedure due to congestion on the Airinterface

FORMULA B7.2 Σ cell (MC04) / SDCCH ASSIGN REQUESTSTHRESHOLD > 5%COMMENT Check SDCCH Erlang : if not critical, SDCCH availability/allocation problem, or HO access on a

nearby cell side effect or interference on the carrier handling SDCCH (the last 2 can lead to highrate of « phantom RACH »)

REF NAME SDNACGR UNIT %

(G) means that the indicator is Global, i.e. it is important to provide it at a Network level.

INDICATOR SDCCH ASSIGN REQUESTS

DEFINITION Number of SDCCH seizure requests during radio link establishment procedureFORMULA B7.2 Σcell (MC148 + MC04)THRESHOLDCOMMENT This includes requests rejected due to congestion on SDCCHREF NAME SDNARQN UNIT Number


1.98

DESCRIPTION OF GLOBAL INDICATORSSDCCH CONGESTION rate

2.4 Description of global indicatorsSDCCH congestion rate

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS > SDCCH > Assignment phase

SDNACGR: SDCCH assignment failure rate due to congestion (Global)


1.99

SDCCH DROP rateUser impact: call setup failure

2.4 Description of global indicatorsSDCCH drop rate

INDICATOR(G)

SDCCH DROP RATE

DEFINITION Rate of dropped SDCCH (SDCCH is established for any transaction OC, TC, LU,etc.)FORMULA B7.2 Σcell (MC138 + MC07 + MC137) / SDCCH ASSIGN SUCCESSTHRESHOLD > 4%COMMENT Drop radio + Drop HO + Drop BSSREF NAME SDCDR UNIT %

In a dense network SDCCH drop rate should be lower than 1%. Indeed the probablity to drop a radio link when the MS is on SDCCH is less than on TCH since the SDCCH phase is shorter (less than 5 seconds) than TCH phase (several tens of seconds).

INDICATOR SDCCH ASSIGN SUCCESS

DEFINITION Total number of SDCCHs successfully seized by mobile during radio link establishmentprocedure

FORMULA B7.2 Σcell (MC01 + MC02)THRESHOLDCOMMENTREF NAME SDNASUN UNIT Number


1.100

TCH ASSIGN UNSUCCESS rate: congestionradio problemBSS problems

2.4 Description of global indicatorsTCH assign unsuccess rate

INDICATOR(G)

TCH ASSIGN UNSUCCESS RATE

DEFINITION Rate of unsuccessful RTCH seizures for normal assignment purpose (congestion + HO&radiofailures)

FORMULA B7.2 (TCH ASSIGN REQUESTS – TCH ASSIGN SUCCESS) / TCH ASSIGN REQUESTSTHRESHOLD > 3%COMMENTREF NAME TCNAUR UNIT %

In a dense network, the TCH assignment unsucess rate should be lower a 1%.

INDICATOR TCH ASSIGN REQUESTS

DEFINITION Number of TCH seizure requests for normal assignment procedureFORMULA B7.2 Σ cell (MC703 + MC812)THRESHOLDCOMMENT This includes requests rejected due to congestion

In B7 : MC703 = MC16 (B6) but per TRXIn B7.1 : MC812 = MC612 (B6)In B7.2 : MC812 = [MC612(B6)]+[Congestion on Abis(C612e)]Congestion on Abis in restriction in B7.2, so finally MC812 = MC612 (B6)

REF NAME TCNARQN UNIT Number

INDICATOR TCH ASSIGN SUCCESS

DEFINITION Number of TCHs successfully seized by the MS for normal assignment procedureFORMULA B7.2 Σ TRX (MC718)THRESHOLDCOMMENT MC718 is new in B7.

MC718 = MC18 (B6) but per TRX.So indicator extended per TRX in B7

REF NAME TCNASUN UNIT Number


1.101

GLOBAL RADIO CONGESTION LEVEL (TCH congestion rate)Subscriber impact: call setup failureMore a management indicator: % of network which has congestion

S2: GLOBAL 2.4 Description of global indicatorsGlobal radio congestion level

INDICATOR(G)

GLOBAL RADIO CONGESTION LEVEL

DEFINITION Global radio congestion level : number or rate of cells recurrently congestedFORMULA B7.2 COUNT_OF_CELLS (AVERAGE (MAX (TCH ASSIGN FAIL CONG RATE)) > 2%))THRESHOLD According to operatorCOMMENT This indicator reports the global radio congestion rate on the network. We define a specific

indicator counting the number of cells that are in congestion in a recurrent manner.MAX (TCH ASSIGN FAIL CONG RATE) : is the peak of failures due to congestion observedduring the period (the day normally). See the definition of TCH ASSIGN FAIL CONG RATE in theQuality of Service chapter)AVERAGE: is an averaging function of the blocking rate over the selected period, that is over BHof days for a week, or over BH of weeks for a monthCOUNT_OF_CELL : is a function counting the number of cells for which condition between () isrespected.The number of cells can be used as indicator, or the rate of cells over the total number of cells in thenetwork or area.

REF NAME QSCGR UNIT Number

This counter intends to give a measurement of the TCH congestion of the whole network.It is implemented on the Alcatel tools but other indicators can be defined.


1.102

CALL DROP rate: The most important indicatorUsed with call setup success rate to compare PLMN (GSM and otherone)Subscribers impact: call drop!!

2.4 Description of global indicatorsCall drop rate

INDICATOR(G)

CALL DROP RATE

DEFINITION Rate of dropped calls (system + radio+ HO + preemption) over the total amount of calls with asuccessful end

FORMULA B7.2 Σcell (MC621 + MC14c + MC736 + MC739 + MC921c) / TCH SUCCESS ENDTHRESHOLD > 4%COMMENT Drop system + Drop radio + Drop HO + Drop preemption

TCH drops occurring after successful assignment but before speech connection are considered ascall drops even if from the customer point of view it is a call setup failureMC739, MC736 and MC621 derive from B6 counters C139, C136 and C21. These new countersare per TRXMC921c is new in B7.2

REF NAME QSCDR UNIT %

In a dense network, the Call Drop Rate should be lower than 2%. It should even go down to 1% or less in case Slow Frequency Hopping is used.

The RTCH drop rate is defined below:

The TRX TCH drop radio rate is defined below:

INDICATOR GLOBAL TCH DROP

DEFINITION Rate of TCHs dropped (system + radio + handover + preemption) over the total amount ofcalls established in the cell

FORMULA B7.2 Σcell (MC14c + MC739 + MC736 + MC621+ MC921c) / TCH SUCCESS BEGINTHRESHOLD > 3%COMMENT Drop System + Drop radio + Drop HO + Drop preemption

Indicator relevant at cell level mostly.MC739, MC736 and MC621 derive from B6 counters C139, C136 and C21. These new

counters are per TRXMC921c is new in B7.2

REF NAME QSTCCDR UNIT %

INDICATOR TRX TCH DROP RADIO RATE

DEFINITION Rate of TCHs dropped due to radio problems, per TRXFORMULA B7.2 (MC736) / TCH SUCCESSTHRESHOLD > 3%COMMENT New in B7

MC736 derives from B6 counters C136. This new counter in B7 is per TRX.Indicator only per TRX because intracell handovers are taken into account

REF NAME TCAHCDRTR UNIT %


1.103

CALL SETUP SUCCESS rate: the second most important indicatorUsed to compare PLMNSubscriber: call not established at the first attempt

Beware: call setup failures due to a lack of coverage are not taken into account in this indicator!!

No way to quantify them (as there is no initial access)

2.4 Description of global indicatorsCall setup success rate

INDICATOR(G)

CALL SETUP SUCCESS RATE (BSS view)

DEFINITION Rate of calls going until TCH successful assignment, that is not interrupted by SDCCH DROPneither by Assignment failures

FORMULA B7.2 (1 – ( SDCCH DROP / SDCCH ASSIGN SUCCESS ) ) * (1 TCH ASSIGN UNSUCCESS RATE)THRESHOLD > 95%COMMENT SDCCH assignment failures are not considered in CSSR as :

• ghost (spurious) RACH cannot be discriminated from a real access failure• effect of re-attempts performed autonomously by the MS cannot be quantified

REF NAME QSCSSR UNIT %

Ghost Racks which correspond to a valid establishment cause are not identified by the BSS. Therefore they can lead to a high SDCCH assignment failure rate if they are too numerous.As the end user is not impacted by this phenomenon if no SDCCH congestion is induced, the SDCCH assignment phase is not considered in the computation of the Call Setup Success rate provided by Alcatel tools.In a dense network, the Call Setup Success Rate should be greater than 98%.The SDCCH congestion rate should also be considered to have a complete picture of Call Setup efficiency.


1.104

1 call success =1 call successfully establishedWithout any call drop

2.4 Description of global indicatorsCall success rate

INDICATOR(G)

CALL SUCCESS RATE (BSS view)

DEFINITION Rate of calls going until normal release , that is not interrupted by SDCCH DROP, neither byAssignment Failures nor by CALL DROP

FORMULA B6.2 (CALL SETUP SUCCESS RATE) * (1 – CALL DROP RATE)THRESHOLD < 92%COMMENTREF NAME QSCCR UNIT %

In a dense network, the Call Setup Success Rate should be greater than 97%.


1.105

CALL SETUP SUCCESS rate CALL SUCCESS rate

2.4 Description of global indicatorsCall (setup) success rate

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS > Call statistics > Call success

QSCSSR: Call setup success rate (Global)QSCCR: Call success rate (Global)


1.106

2.4 Description of global indicatorsHandover cause distribution

Indicator aiming at measuring the efficiency of planning /optimization

INDICATOR(G)

HO CAUSE DISTRIBUTION

DEFINITION Distribution of Handover attempts by cause X : UL/DL Qual, UL/DL Lev, UL/DL Interference,Distance, Better Cell, Interband, Micro cells HO, Concentric cell, Traffic, AMR, TFO causes.

FORMULA B7.2 Σ cell (MC67w or MC785x or MC586y or MC10zz or MC447 or MC461)Σcell (MC67all + MC785all + MC586all + MC10all + MC447 + MC461)

MC67all = MC671+MC672+MC673+MC674+MC675+MC676+MC677+MC678+MC679+MC670MC785all = MC785a + MC785d + MC785e + MC785f (microcell)MC586all = MC586a + MC586b + MC586c (concentric)MC10all = MC1040 + MC1044 + MC1050

THRESHOLD Quality DL > 10%, Qual UL > 10%, Level UL > 20%, Level DL > 20%Interf UL > 5%, Interf DL > 5%, Better Cell < 30%

COMMENTREF NAME HCSTBPBR, HCCCELVDR, HCCCELVUR, HCCCBCPR,

HCSTEDIR, HCSTEIFDR, HCSTELVDR, HCSTEQLDR,HCSTBDRR, HCMBBCPR, HCMCEBSR, HCMCELVDR,HCMCBCPR, HCMCELVUR, HCSTEMIR, HCSTEIFUR,HCSTELVUR, HCSTEQLUR, HCSTAMR, HCSTBTFR

UNIT %


1.107

2.4 Description of global indicatorsHandover standard cause distribution

Indicator aiming at measuring the efficiency of planning / optimizationInteresting for comparing HO distribution after concentric or micro cell implementation

INDICATOR(G)

DISTRIBUTION HO CAUSE STANDARD

DEFINITION Distribution of Handover attempts by standard cause : Power Budget, quality too low, level too low,high interference and MS-BTS distance too long.

FORMULA B7.2Σ cell ( (MC67x) / GLOBAL HO CAUSE STANDARD)

MC67x = MC670 or MC672 or MC671 or MC673 or MC676 or MC677 or MC678 or MC674 or(MC670+MC672) or (MC671+MC673) or (MC676+M677)

THRESHOLDCOMMENTREF NAME HCSTEIFDSR, HCSTEIFUSR, HCSTEIFSR, HCSTELVDSR,

HCSTELVUSR, HCSTELVSR, HCSTEQLDSR,HCSTEQLUSR, HCSTEQLSR, HCSTBPBSR, HCSTEDISR

UNIT %

The Global HO cause standard indicator is defined as below:

where: MC670: Number of handover attempts cause 2: "uplink quality too low" MC672: Number of handover attempts cause 4: ”downlink quality too low" MC671: Number of handover attempts cause 3: "uplink level too low"MC673: Number of handover attempts cause 5: "downlink level too low"MC676: Number of handover attempts cause 15: "too high uplink interference level"MC677: Number of handover attempts cause 16: "too high downlink interference level"MC678: Number of handover attempts cause 12: "too low power budget"MC674: Number of handover attempts cause 6: "MS-BTS distance too long"


1.108

2.4 Description of global indicatorsHandover cause distribution

HANDOVER CAUSE rates

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover statistics INDICATORS > Handover causes

HCXXYYYYR: Rate of specific HO cause xxyyyy versus all HO causes (Global)where XX = ST (standard) or MC (micro cell) or CC (concentric cell) or MB (multi band)and YYYY is specific to the cause


1.109

Global success rate of Outgoing HO

Success rate of execution of Outgoing HO

2.4 Description of global indicatorsOutgoing handover success rate

INDICATOR(G)

OUTGOING HO SUCCESS RATE

DEFINITION Rate of successful outgoing external and internal intercell SDCCH and TCH handoversFORMULA B7.2 Σcell (MC646 + MC656) / Σcell (MC645a + MC655a)THRESHOLD < 90%COMMENT This indicator includes preparation and execution.REF NAME HOORSUR UNIT %

INDICATOR(G)

EFFICIENCY OF OUTGOING HANDOVER EXECUTION

DEFINITION Rate of successful outgoing external and internal intercell SDCCH and TCH handoversFORMULA B7.2 Σcell (MC646 + MC656) / Σcell (MC650 + MC660)THRESHOLD < 90%COMMENT This indicator takes into account HO execution only (not ho preparation).REF NAME HOOREFR UNIT %

Global Outgoing HO success rate: represents the global efficiency ot the outgoing handovers performed from one cell to any of its neighboring cells (same BSS or not).Efficiency of Outgoing HO execution: represents the efficiency of the channel change procedure during outgoing handovers performed from one cell to any of its neighboring cells (same BSS or not). It does not take into account the HO failures that can occur during the preparation phase when the new channel is being selected and activated.

From B7 MC645A replaces MC645 of B6.


1.110

Global success rate of Incoming HO

Success rate of execution of Incoming HO

2.4 Description of global indicatorsIncoming handover success rate

INDICATOR(G)

INCOMING HANDOVER SUCCESS RATE

DEFINITION Rate of successful incoming external and internal intercell SDCCH and TCH handovers.FORMULA B7.2 Σcell (MC642 + MC652) / Σcell(MC820 + MC830)THRESHOLD < 90%COMMENTREF NAME HOIRSUR UNIT %

INDICATOR(G)

EFFICIENCY OF INCOMING HANDOVERS

DEFINITION Rate of successful incoming external and internal intercell SDCCH and TCH HOsFORMULA B7.2 Σcell (MC642 + MC652) / Σcell (MC821 + MC831)THRESHOLD < 90%COMMENT Excluding congestion failures and BSS preparation failures from requests.REF NAME HOIREFR UNIT %

Global Incoming HO success rate: represents the global efficiency of the incoming handovers performed to one cell from any of its neighboring cells (same BSS or not).Efficiency of Incoming HO execution: represents the efficiency of the channel change procedure during incoming handovers performed to one cell from any of its neighboring cells (same BSS or not). It does not take into account the HO failures that can occur during the preparation phase when the new channel is being selected and activated.


1.111

The highest, the best is the cellBut the traffic handled is not taken into account

2.4 Description of global indicatorsCall quality factor absolute

INDICATOR(G)

CELL QUALITY FACTOR ABSOLUTE

DEFINITION Indicator summarizing the cell behavior and allowing the operator to sort out cell for investigation.This indicator is based on failure events. For each part of the indicator,twothresholds are used: Topt and TQoS. TQoS is the QoS warning threshold (e.g. above or belowthe threshold, a warning is generated on the cell. Topt + TQoS is the optimal valuethat should be acheived. Each part as a weighting factor (WF) according to the impact on the subscriber’s point of view.

investigation. This indicator is based on failure events. For each part of the indicator, two

FORMULA B6.2 ((1 – SDCCH CONGESTION rate) - TQoS)/ Topt * WF+ (CALL SETUP SUCCESS rate - TQoS)/ Topt *WF+ ((1 – CALL DROP rate - TQoS)/ Topt * WF+ (OUTGOING HO SUCCESS rate - TQoS)/ Topt * WF+ ((1 – HO QUALITY rate - TQoS)/ Topt * WF

THRESHOLD SDCCH CONGESTION rate : TQoS = 0.97, Topt = 0.03, WF = 0.1CALL SETUP SUCCESS rate : TQoS = 0.9, Topt = 0.09, WF = 0.2CALL DROP rate : TQoS = 0.96, Topt = 0.04, WF = 0.3OUTGOING HO SUCCESS rate : TQoS = 0.85, Topt = 0.12, WF = 0.15HO QUALITY rate : TQoS = 0.85, Topt = 0.1, WF = 0.25

COMMENTREF NAME QSCQAR UNIT %

This counter intends to compute for every cell of the network a global indicator taking into account the major causes of bad Quality of Service.Each cause is weighted according to the impact on the end user.


1.112

For optimizationTry to improve cells with the worst CQFR

2.4 Description of global indicatorsCall quality factor relative

INDICATOR(G)

CELL QUALITY FACTOR RELATIVE

DEFINITION This indicator is the Cell Quality Factor Absolute weighted by the cell traffic.Investigation shouldbe done in priority on the cell having a high rate of failures with high traffic (the traffic is the rate oftraffic handled by the cell over the total network traffic – traffic is TCH seizure attempts)

FORMULA B7.2 CQFA * ((MC15a + MC15b + MC703)cell / (MC15a + MC15b + MC703)network)THRESHOLD N/ACOMMENTREF NAME QSCQRR UNIT %

Normalizing the previous Cell Quality Factor Absolute by the traffic of the cell will allow to compare the QoS of the cell between each other and raise the list of top worst cells candidate for analysis.From B7, MC703 replaces MC16 of B6.


1.113

Management indicator, maintenance oriented, assessingQuantity of stability problemsReaction time to problems

2.4 Description of global indicatorsNetwork TCH availability

INDICATOR(G)

NETWORK (TCH) AVAILABILITY

DEFINITION Rate of TCHs able to carry traffic (upon the total number of traffic channels)FORMULA B7.2 (Σcell (MC250) / #Available TCH)THRESHOLD < 95%COMMENT #Available TCH : according to channel configurationREF NAME TCAVAR UNIT %


1.114

GLOBAL INDICATORS

2.4 Description of global indicatorsExercise

Indicator value OK ? Impact

SDCCH congestion 10 % NOK difficulties to establish call

Call drop 5 %

Call success 95 %

Efficiency of outgoing HO 91 %

Network TCH availability 94 %

TCH assignment failure 2,4 %

Call drop 2,3 %

SDCCH drop 2 %

HO cause distribution(ratio of better cell)

45 %

Call success 88 %

SDCCH drop 1 %

Time allowed: 10 minutes



2 GLOBAL INDICATORS

2.5 Traps and restrictions of global indicators


1.116

2.5 Traps and restrictions of global indicatorsObjective

Beaware of traps and restrictions about some global indicators

So as to be able to provide a reliable interpretation


1.117

2.5 Traps and restrictions of global indicatorsCall set-up success rate / Call drop rate

CALL SETUP SUCCESS The radio link establishment failure is not taken into account, because:

most of failures during RLE are due to ghost RACHthe MS is attempting MAX_RETRANS+1 times before giving updifficult to assess subscriber's impact, anyhow very low

CALL DROPFor BSS, the last stage is considered as established, although it is not the cause from a user point of viewIf a TCH drop occurs during this phase

for the user, it is a setup failurefor the OMC-R indicators, counted as a call drop


1.118

2.5 Traps and restrictions of global indicatorsCall duration

IMPACT OF CALL DURATION

The longest a call is, the highest the risk to have a drop isIf statistics are done on abnormally long or short calls, the result can be less accurate Typical case: drive testTypical call duration: 80/90 seconds in most of European countries


1.119

2.5 Traps and restrictions of global indicatorsMobility

IMPACT OF MOBILITYMost of drop problems are due to mobility

Usually 2/3 of calls are static (no HO will be done)For example, if 40 drops are observed for 1000 calls

40/1000 = 4% of global call dropbut most of call drops are generated by "moving calls"

40/(1000*1/3) = 40/333 = 12 % of call drop rate for moving call0 % for static call

Typical trap when comparing drive tests results with OMC-R statistics


1.120

2.5 Traps and restrictions of global indicatorsExercise

TRAPS AND RESTRICTIONS OF GLOBAL INDICATORS: Case conclusion OK ? why

global call drop : 2% for 1 call of 20 mn,The risk of drop is 2%

NOK The call duration is higher than the average

In 1 BSS, some transcoders arefaulty : as soon as TCHs areestablished on these TCs, they are lost

The call setup successrate indicatorwill beincreased due to thisproblem

In 1 network, drive test are showinga general call drop of 7%. The OMC-R call drop indicator isgiving 2.1%.

The OMC-R indicatoris erroneous (drive

test is the reality)

In 1 network, the global call setup success is 92 %

For moving calls, callsetup success will beabout 76 %

In a pedestrian zone, 80 % of callsare static

The measured call drop is 1,7 %

For taxi, calldone in Taxi in this zone willbe droppedat 5.1 %




2 GLOBAL INDICATORS

2.6 Global indicators interpretation


1.122

2.6 Global indicators interpretation Exercise 1

Is this network OK? N a m e v a lu e

S D C C H c o n g e s t i o n 1 %

S D C C H d r o p 3 %

T C H a s s i g n m e n t f a i l u r er a t e

2 %

C a l l d r o p 1 %

C a l l s e t u p s u c c e s s r a t e 9 6 %

C a l l s u c c e s s r a t e 9 4 %

E f f i c i e n c y o f o u t g o i n gH O

9 2 %

E f f i c i e n c y o f i n c o m in gH O

9 3 %

H O c a u s e d i s t r i b u t i o nb e t t e r / l e v e l / q u a l i t y

7 0 / 2 0 / 1 0

N e t w o r k T C Ha v a i l a b i l i t y

9 8 %



1.123


Can one say that : all indicators are OK? the coverage of the network is 95%? the call success of all the cells are 95% (minimum)?

N a m e v a l u e

S D C C H c o n g e s t i o n 5 %

S D C C H d r o p 2 %

T C H a s s i g n m e n t f a i l u r er a t e

1 %

C a l l d r o p 1 %

C a l l s e t u p s u c c e s s r a t e 9 7 %

C a l l s u c c e s s r a t e 9 5 %

E f f i c i e n c y o f o u t g o i n gH O

9 2 %

E f f i c i e n c y o f i n c o m i n gH O

9 2 %

H O c a u s e d i s t r i b u t i o nb e t t e r / l e v e l / q u a l i t y

7 5 / 1 5 / 1 0

N e t w o r k T C Ha v a i l a b i l i t y

9 8



1.124


Results of field tests on a network

Is the network better if QSCDR = 2%?

Name value

SDCCH congestion

SDCCH drop

TCH assignment failurerateCall drop 4.6 %

Call setup success rate 92 %

Call success rate

Efficiency of outgoingHOEfficiency of incomingHOHO cause distributionbetter/level/qualityNetwork TCHavailability




3. DETAILED INDICATORS


1.126

3 Detailed indicatorsSession presentation

Objective: to be able to use the BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS document in order to get some more detailed indicators of the Alcatel BSS

Program: 3.1 Indicator reference name3.2 Indicators classification




3.1 Indicator reference name


1.128

3.1 Indicator reference nameDescription

each QOS indicator has a unique REFERENCE NAME of 10 characters

UnitFamily

Procedure Type JokerPrefix Sub-type

mandatory

optional




3.2 Indicators classification


1.130

3.2 Indicators classification Main categories

Classification in BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS document

Control Channels

SCCP

TCH

SDCCH

Traffic load

Call statistics

RTCH

SDCCH

Global QoS

Couple of cells

SDCCH /TCHHO repartition

Intracell HO

Incoming HO

Outgoing HO

HO causes

Handoverstatistics

Resourceavailability

Multiband

Multilayer / MultibandNetwork

Concentric cells

Directed retry

Densificationtechniques

GSMindicators


1.131

3.2 Indicators classification SDCCH traffic

Traffic Load and Traffic Model > SDCCH traffic

Estab

SDCCH Traffic

TrafficMT

TrafficMO

Loc. Update

IMSI Detach

Sup. Service

Call

LU Follow on

SMS

CallRe-Estab

Other

MSPenetration Rate

TrafficDual Band

ResourceOccupancy

SDCCHErlang

SDCCH MeanHolding TimeGlobal

Traffic

GlobalRequests

TrafficModel

HandoverNormalAssignment

NormalAssignment

Handover

The Traffic model section includes indicators for: – number of SDCCH connection requests and successses (Immediate Assignment, HO).– distribution of SDCCH connection success (MO and MT connections versus all MO+MT connections, type of MO

connections versus all MO connection types).

The MS penetration rate section includes the indicator for: – percentage of multiband MS SDCCH access (except LU) versus all MS SDCCH accesses.

The Resource occupancy section includes indicators for: – SDCCH traffic in Erlang.– average duration in seconds of SDCCH channel usage.


1.132

3.2 Indicators classification TCH traffic

Traffic Load and Traffic Model > TCH traffic

RTCH Traffic

ResourceOccupancy

TCHErlang

Full RateErlang

Full RateAllocated

Full RateMean TCH

Time

Half RateErlang

Half RateAllocated

Half RateMean TCH

Time

Blocking Peak

Ratio ofHR Traffic

TCHMultibandOccupancy

Traffic Model

REQUESTSAssign / HO / DR

SUCCESSAssign / HO / DR

HO PER CALL

REQUESTSFR, DR, DR/EFR, AMR, DATA

Speech Version&Channel Type

ALLOCATIONSFR, HR, EFR, AMR, DATA

SUCCESSAMR / TFO

The Speech Version and Channel Type section includes indicators for: – distribution of TCH allocation requests (FR/DR/DR+EFR/AMR/DATA).– distribution of TCH allocation successes (FR/DR/DR+EFR/AMR/DATA).– rate of TCH AMR allocation successes.– rate of TFO calls versus all speech calls.

The Traffic model section includes indicators for: – number of TCH connection requests and successes (Normal Assignment, HO, DR).– rate of TCH allocation successes for HO+DR versus all TCH allocations (NA+HO+DR).– number of HOs per call.

The Resource occupancy section includes indicators for: – RTCH traffic in Erlang (FR+HR, FR, HR, multiband).– average duration in seconds of RTCH channel usage (FR+HR, FR, HR).– number of TCH FR allocations and number of TCH HR allocations.– rate of TCH HR allocations versus all TCH allocations (FR+HR).– TCH peak of blocking (TCH congestion time).


1.133

3.2 Indicators classificationSCCP resource occupancy / Control channels traffic

Traffic Load and Traffic Model > SCCP resource occupancySCCP traffic in Erlang

Traffic Load and Traffic Model > Control Channels trafficPCH channel loadAGCH channel loadRACH channel load


1.134

3.2 Indicators classificationQoS SDCCH

GLOBAL Quality of service > SDCCH

Drop BSS

SDCCH

EstablishedPhase

Drop Rate

Drop Radio Drop HO

Unsuccess

Congestion

Assignment Phase/

Handover

RadioFailure

BSS Failure

Access Reject

Dynamic Allocation

B8

New B8

(See comments)

The Assignment phase section includes indicators for the Radio Link Establishment procedure: global SDCCH access failure rate. specific SDCCH access failure rate per type of problem (SDCCH congestion, radio, BSS).specific indicators for Dynamic SDCCH Allocation:

Stored Indicators (see Dynamic SDCCH Allocation in the Global Indicators section)DYTROFN.= MC800DYAHCATAN = MC801aDYAHCATMN = MC801bDYAHCASAN. = MC802aDYAHCASMN.= MC802bDYN = number of Dynamic timeslots (given by configuration file) = Cell_NB_DYNComputed indicatorsDYAHCATAR: average rate of busy TCH (FR of HR) allocated on dynamic SDCCH/8 timeslotsFormula: tdiv (DYAHCATAN,DYTROFN,0,0)DYAHCATMR: maximum rate of busy TCH (FR of HR) allocated on dynamic SDCCH/8 timeslotsFormula: tdiv (DYAHCATMN,DYTROFN,0,0)DYAHCASAR: average rate of busy SDCCH sub-channels allocated on the dynamic SDCCH/8timeslotsFormula: tdiv (DYAHCASAN,DYTROFN,0,0)Impact on existing Indicators: Apart of modification due to introduction of Dynamic SDCCH/8 timeslot, the general formula of these indicators are redesigned, to be simpler.TCRRDN, TCRROFN, TCAHCGUN, TCAVAR (removed as it is the same as TCTRAR), TCTRAVE, TCTRAR, TCTRTCE, SDAHCGUN, SDAVAR, SDRRDN, SDRROFN, SDTRAVE

The Handover procedure section includes the indicator for the preparation of the SDCCH HO procedure: rate of SDCCH HO failure due to SDCCH congestion

The Established phase section includes indicators for SDCCH Phase: global SDCCH drop rate.specific SDCCH drop rate per type of problem (radio, HO, BSS).

B8


1.135

3.2 Indicators classificationQoS RTCH

GLOBAL Quality of service > RTCH

DirectedRetry

RTCH

Unsuccess

Assignment Phase/

Handover

Global RadioCongestion Level

Congestion

RadioFailure

BSSFailure

EstablishedPhase

Drop rate

Drop Radio

Drop BSS

Drop HO

Preemption

PreemptionPhase

PCI =1 PVI =1

Requests

Allocationwith / withoutPreemption

Failure

Success

Success

QueuingPhase

Queue Length

AssignQueuing Fail

AssignQueued

& Reject

QueuedSuccess

Queue Full

HigherPriority

Timeout

AssignQueued

NormalAssign.

The Assignment phase section includes indicators for the TCH Normal Assignment procedure: global RTCH assignment failure rate (called unsuccess rate).specific RTCH assignment failure rate per type of problem (RTCH congestion, radio, BSS).global radio congestion level (number of cells congested in the network).

The Handover procedure section includes indicators for the global HO procedure (intracell+intercell internal + intercell external): rate of RTCH incoming HO failure due to RTCH congestion.specific RTCH outgoing HO failure rate per type of problem (congestion, radio - Reversion Old Channel, radio drop, BSS).


1.136

3.2 Indicators classificationQoS call statistics

GLOBAL Quality of service > Call statistics

Call Statistics

Call Success

Call SetupSuccess Rate

CallSuccess Rate

Cell QualityFactor Absolute

Cell QualityFactor Relative

Call Drop

Call Drop Rate

Drop Radio Drop BSSDrop HO

Transcoder Failure

BSS Internal Failure

Call DropEnd User Rate

Preemption

The Call Drop section includes indicators for the TCH Phase: global call drop rate.specific call drop rate per type of problem (radio, HO, BSS int., TransCoder, preemption).

The Call Success section includes indicators for the global call procedure (speech): rate of call setup success.rate of call success.global cell quality factor.


1.137

Handover STATISTICS > Handover causes

3.2 Indicators classificationHandover causes

Handover causes

HO causes

All HO

cause distribution

Outgoing HO Incoming HOHO standard

cause distribution

HO cause category

distribution

HO causes per Adjacency

HO cause category

distribution

B8

Fast traffic HO taken into account

New type of counter for dual band HO

(See comments)

New B8

The Handover causes section includes indicators of HO causes distribution corresponding to outgoing handovers relating to a cell: distribution of HO causes taking into account all possible HO causes (quality UL, level DL, distance, power budget,

concentric cell cause, micro cell cause, traffic, etc.).distribution of HO standard causes taking into account only HO standard causes (quality UL, quality DL, level UL, level DL,

interference UL, interference DL, distance, power budget).

The Handover causes per adjacency section includes indicators of HO causes distribution corresponding to outgoing and incoming handovers relating to a couple of serving/target cells:

distribution of HO cause categories taking into account 3 categories (emergency [quality, level, interference, distance, power budget]), better condition [power budget, capture], traffic, forced directed retry).

B8: Introduction of C449 (type 6) in type 110 (as MC449) improves the result of all HO cause Indicators:C449 = MC449 = number of handover attempts with cause 28 (Fast traffic handover)The Indicator TOTALHO (HCN) is impacted as well as the following indicators:

HCSTBPBR, HCCCR, HCSTEDIR, HCSTEDMR, HCSTIFDR, HCSTLVDR, HCSTQLDR, HCSTEIFR, HCSTELVR, HCMCR, HCSTEQLR, HCSTIFUR, HCSTLVUR, HCSTQLUR, HCNTBDR, HCSTBTFR, HCSTAMR, HCSTAMFR, HCSTAMHR, HCSTBTRFR

B8: Introduction of a new type of counter (Type 32: Change of frequency band measurements)Type 32 is defined as Standard and provides information to observe handovers between different frequency bands.C403a = NB_INC_EXT_TCH_HO_NEW_BAND_ATPT = Number of incoming external TCH (in HR or FR usage) handover attempts including a change of the (TCH) frequency band.C403b = NB_INC_EXT_TCH_HO_NEW_BAND_SUCC = Number of incoming external TCH (in HR or FR usage) handover successes including a change of the (TCH) frequency band.C404a = NB_OUT_EXT_TCH_HO_NEW_BAND_ATPT = Number of outgoing external TCH (in HR or FR usage) handover attempts including a change of the (TCH) frequency band.C404b = NB_OUT_EXT_TCH_HO_NEW_BAND_SUCC = Number of outgoing external TCH (in HR or FR usage) handover successes including a change of the (TCH) frequency band.C420a = NB_INC_INT_TCH_HO_NEW_BAND_ATPT = Number of incoming internal TCH (in HR or FR usage) handover attempts including a change of the (TCH) frequency band.C420b = NB_INC_INT_TCH_HO_NEW_BAND_SUCC = Number of incoming internal TCH (in HR or FR usage) handover successes including a change of the (TCH) frequency band.C421a NB_OUT_INT_TCH_HO_NEW_BAND_ATPT = Number of outgoing internal TCH (in HR or FR usage) handover attempts including a change of the (TCH) frequency band.C421b NB_OUT_INT_TCH_HO_NEW_BAND_SUCC = Number of outgoing internal TCH (in HR or FR usage) handover successes including a change of the (TCH) frequency band.

B8


1.138

Handover STATISTICS > Outgoing handovers

3.2 Indicators classificationOutgoing handovers

Failure With Reversion

Call Drop Rate

Efficiency

Preparation Success Rate

Intra-BSC


Call Drop Rate

Efficiency


External

Call Drop Rate

Efficiency

Success Rate

Intra-BSC & External

Outgoing HO

B8

New B8 New LAPD counter to analyze the cause of delay in HO procedures

The Outgoing Intra BSC intercell section includes indicators corresponding to the efficiency of outgoing intercell internal handovers relating to a cell (serving):

efficiency ot the preparation phase (target TCH allocation) of the outgoing handovers performed from one cell to any of its neighboring cells belonging to the same BSS.

efficiency ot the execution phase (old to new TCH channel change) of the outgoing handovers performed from one cell to any of its neighboring cells belonging to the same BSS.

distribution of outgoing intra BSC intercell HO failures per type of problem (radio drop, radio - Reversion Old Channel, BSS).

The Outgoing Inter BSC intercell section includes indicators corresponding to the efficiency of outgoing intercell external handovers relating to a cell (serving):

efficiency ot the preparation phase (target TCH allocation) of the outgoing handovers performed from one cell to any of its neighboring cells not belonging to the same BSS.

efficiency ot the execution phase (old to new TCH channel change) of the outgoing handovers performed from one cell to any of its neighboring cells not belonging to the same BSS.

distribution of outgoing inter BSC intercell HO failures per type of problem (radio drop, radio - Reversion Old Channel, BSS).

The Outgoing Intra BSC + Inter BSC intercell section includes indicators corresponding to the efficiency of all outgoing intercellhandovers relating to a cell (serving):

global efficiency ot the outgoing handovers performed from one cell to any of its neighboring cells whether they belong to the same BSS or not

efficiency ot the execution phase (old to new TCH channel change) of the outgoing handovers performed from one cell to any of its neighboring cells whether they belong to the same BSS or not.

outgoing intra BSC + inter BSC intercell HO drop rate per type of problem (radio drop, radio - Reversion Old Channel, BSS).

When the BSC is congested on the downlink, some messages are discarded. This may result for example in call establishment failures, loss of paging messages or delay in handover procedures.

A new LapD counter that indicates the time an LapD link is congested is created to analyze the cause of a degraded quality of service. This counter is implemented in type 7 and thus is only available in a detailed measurement campaign.


B8

(See comments)


1.139

Handover STATISTICS > Incoming handovers

3.2 Indicators classificationIncoming handovers

Failure BSS

Failure Radio

Congestion

Efficiency

Intra-BSC

Failure BSS

Failure Radio

Failure No CIC

Congestion

Efficiency

External

Efficiency

Intra-BSC & External

Incoming HO

B8

New counters and indicators for:

Incoming external HO 3G - > 2G

Incoming external HO 2G - > 2G only

New B8

(See comments)

The Incoming Intra BSC intercell section includes indicators corresponding to the efficiency of incoming intercell internal handovers relating to a cell (target):

efficiency ot the execution phase (old to new TCH channel change) of the incoming handovers performed to one cell from any of its neighboring cells belonging to the same BSS.

distribution of incoming intra BSC intercell HO failures per type of problem (congestion, radio, BSS).

The Incoming Inter BSC intercell section includes indicators corresponding to the efficiency of incoming intercell external handovers relating to a cell (target):

efficiency ot the preparation phase (target TCH allocation) of the incoming handovers performed to one cell from any of its neighboring cells not belonging to the same BSS.

distribution of incoming inter BSC intercell HO failures per type of problem (RTCH congestion, TTCH (CIC) congestion, radio, BSS)

Using new counters introduced in B8 for 3G to 2G Incoming External Handovers,MC922a: NB_INC_EXT_3G_2G_HO_REQ (REQUESTS)MC922b: NB_INC_EXT_3G_2G_HO_SUCC (SUCCESS)MC922c: NB_INC_EXT_3G_2G_HO_EXEC_FAIL_MS_ACC (FAILURES)MC922d: NB_INC_EXT_3G_2G_HO_ATPT (ATTEMPTS)

Creation of 4 new stored indicators based on the 4 new counters: HOIMRQUN= MC922a HOIMSUUN = MC922b HOIMFLRRUN = MC922c HOIMCAUN = MC922d

As existing PM counters related to incoming handovers keep a global view, so consider handovers from 2G cells as well as handovers from 3G cells. The pure 2G-2G results can then be obtained by comparing them with the new introduced counters:

Creation of 4 new stored indicators for incoming external handover 2G -2G only: HOIMRQGN = MC820 - MC922a (REQUESTS) HOIMSUGN = MC642 - MC922b (SUCCESS)HOIMFLGN = MC643 - MC922c (FAILURES) HOIMCAGN = MC821 - MC922d (ATTEMPTS)

And New calculated indicators are defined: 3G-2G HO Success rate: HOIMSUUR = MC922b / MC922a2G-2G HO Success rate: HOIMSUGR = (MC642-MC922b) / (MC820-MC922a)preparation and execution 3G-2G HO failure rate HOIMFLUR = 1 -(MC922b/MC922a)preparation and execution 2G-2G HO failure rate HOIMFLGR = 1 -((MC642-MC922b) / (MC820-MC922a))

B8


1.140

Handover STATISTICS > Intracell handovers

3.2 Indicators classificationIntra-cell handovers

CDR Radio CDR BSS


Failure BSS

Call Drop Rate

Congestion

Efficiency

Intracell HO

The Intracell section includes indicators corresponding to the efficiency of intracell handovers performed within a cell: efficiency ot the execution phase (old to new TCH channel change) of the intracell handovers performed within a cell.distribution of intracell HO failures per type of problem (congestion, radio drop, radio - Reversion Old Channel, BSS).


1.141

Handover STATISTICS > Handover statistics per couple of cell

3.2 Indicators classificationHandover statistics per couple of cells

HO Success Distribution

Success Rate

Efficiency


HO statisticsper Couple of Cell

The Indicators with counters type 180 section includes indicators corresponding to the efficiency of incoming internal+external intercell SDCCH+TCH handovers performed between two cells (serving/target):

global efficiency of the incoming intercell handovers performed between two cells (serving/target).efficiency ot the preparation phase (old to new TCH channel change) of the incoming intercell handovers performed

between two cells (serving/target).efficiency ot the execution phase (old to new TCH channel change) of the incoming intercell handovers performed between

two cells (serving/target).distribution per couple of (serving/target) cells of the incoming intercell handovers performed to a cell from any of its

neighboring cells whether they belong to the same BSS or not.



4 HANDOVER INDICATORS


1.143

4 Handover indicatorsSession presentation

Objective: to be able to explain what are the main Handover counters and indicators provided by the Alcatel BSS in order to monitor the quality of handovers

Program: 4.1 Intra-cell handover indicators per cell4.2 Internal handover indicators per cell4.3 External handover indicators per cell4.4 Handover indicators per couple of cells




4.1 Intra-cell handover indicators per cell


1.145

4.1 Intra-cell handover indicators per cell Handover types

HO FAIL. CASES > HO ReminderIntra-Cell: Handover between two TCHs of the same cellInternal

between two cells of the same BSCalso called intra BSCand not using the forced external handover mode

Externalbetween two cells of different BSCsalso called inter BSCor between two cells of the same BSC when using the forced external handover mode

TCH/(SDCCH) HandoverSynchronous

between 2 cellssharing the same clockscollocatedusually 2 sectors of the same BTS

tunable at OMC-R level

Asynchronousnot synchronous for any reasonno dedicated monitoring for synchronous/asynchronous HO

Incomingas considering the target cell

Outgoingas considering the serving cell


1.146

4.1 Intra-cell handover indicators per cell Intracell HO - success

HO FAIL. CASES > intracell HO > successful caseMS BTS BSC MSC

MEAS REPORT-----------------------------> MEASUREMENT RESULT

--------------------------------------------------------------> MC870PHYSICAL CONTEXT REQUEST (old channel)<--------------------------------------------------------------PHYSICAL CONTEXT CONFIRM (old channel)

-------------------------------------------------------------->CHANNEL ACTIVATION (new channel)

<--------------------------------------------------------------CHANNEL ACTIVATION ACK (new channel)

-------------------------------------------------------------->ASSIGNMENT CMD ASSIGNMENT COMMAND (old channel) MC871

<----------------------------- <-------------------------------------------------------------- start T3107SABM

-----------------------------> ESTABLISH INDICATION (new channel)UA -------------------------------------------------------------->

<-----------------------------ASSIGNMENT CMP ASSIGNMENT COMPLET(new channel)-----------------------------> --------------------------------------------------------------> stop T3107

MC662HANDOVER

PERFORMED------------------->

RF CHANNEL RELEASE (old channel)<--------------------------------------------------------------

RF CHANNEL RELEASE ACK (old channel)-------------------------------------------------------------->

Both SDCCH and TCH are counted together.The T3107 timer is also used as the guard timer of the channel change procedure during an intra cell handover. The Default valuefor T3107 is 14 seconds.


1.147

4.1 Intra-cell handover indicators per cell Intracell HO - failures

HO FAIL. CASES > intracell HO failures

Handover Preparation: congestion BSS problem (no specific counter)

Handover Execution: reversion to old channeldrop radioBSS problem (no specific counter)


1.148

HO FAIL. CASES > intracell HO failure: congestionMC561TCH+MC101SDCCH

4.1 Intra-cell handover indicators per cell Intracell HO - congestion

MS Serving BTS Serving BSC MSC


--------------------------------------------------------------> MC870No free TCH

MC561

From B7, MC561 replaces MC61of B6.As the counting of the Abis-TCH congestion case is in restriction in B8:

MC61(B6) = MC561(B7)


1.149

4.1 Intra-cell handover indicators per cell Intracell HO - radio failure ROC

HO FAIL. CASES > intracell HO failure: reversionold channel

Serving ServingMS BTS BSC MSC

MC871ASSIGNMENT CMD ASSIGNMENT COMMAND (old channel)<----------------------------- <----------------------------------------------------------------- start T3107 (= T10)start T200

SABM (new channel)-----------------------------> ESTABLISH INDICATION (new channel)

----------------------------------------------------------------->UA (new channel)

X- - - - - --------------------SABM (new channel)

----------------------------->UA (new channel)

X- - - - - --------------------

SABM (old channel)-----------------------------> ESTABLISH INDICATION (old channel)

UA (old channel) -----------------------------------------------------------------><-----------------------------ASSIGNMENT FAIL ASSIGNMENT FAILURE-----------------------------> -----------------------------------------------------------------> stop T3107

MC667PHYSICAL CONTEXT REQUEST (new channel)

<-----------------------------------------------------------------PHYSICAL CONTEXT CONFIRM (new channel)

----------------------------------------------------------------->RF CHANNEL RELEASE (new channel)

<-----------------------------------------------------------------RF CHANNEL RELEASE ACK (new channel)

----------------------------------------------------------------->


1.150

HO FAIL. CASES > intracell HO failure: radio dropMC663=C63TCH+C103SDCCH


MC871ASSIGNMENT CMD ASSIGNMENT COMMAND (old channel)<----------------------------- <----------------------------------------------------------------- start T3107 (= T10)

MC663Release of old and new channels T3107 expiry

4.1 Intra-cell handover indicators per cell Intracell HO - radio failure drop


1.151

HO FAIL. CASES > intracell HO failure: BSS drop

no specific counter


MC871ASSIGNMENT CMD ASSIGNMENT COMMAND (old channel)<----------------------------- <----------------------------------------------------------------- start T3107 (= T10)

--------------------------------------- >CLEAR REQUEST

O&M interventionRadio interface failure

4.1 Intra-cell handover indicators per cell Intracell HO - BSS problem

Intra cell HO failures due to BSS problems are deduced from other counters.


1.152

HO FAIL. CASES > intracell HO counters

4.1 Intra-cell handover indicators per cell Intracell HO - counters

Request MC870

Congestion MC561+MC101BSS Pb MC870-MC871-(MC561+MC101)

Attempt MC871

Reversion old channel MC667Drop radio MC663BSS Pb MC871-MC662-MC667-MC663

Success MC662

Preparation

Execution

INTRACELL Handover

REQUEST

CONGESTION

ATTEMPT

REVERSION OLD CHANNEL

DROP RADIO

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure




4.2 Internal handover indicators per cell


1.154

HO FAIL. CASES > internal HO > success case

4.2 Internal handover indicators per cell Internal HO - success

The same inter-cellhandover procedure leads to an incrementation of two sets of counters: incoming HO counters for the target cell: MC830, MC831, MC652, etc.outgoing HO counters for the serving cell: MC655A, MC660, MC656, etc.In HO_PERFORMED MESSAGE

Target cell (CI,LAC)"cause" of HO

MS serving cell target cell BSC MSCMEAS REP

-----------------------> MEASUREMENT RESULT------------------------------------------------------------------------> MC830, MC655A

CHANNEL ACTIVATION<----------------------------------

CHAN ACTIV ACK---------------------------------->

HO CMD HANDOVER COMMAND<----------------------- <------------------------------------------------------------------------ start T3103

MC831, MC660start T3124

HANDOVER ACCESS------------------------------------------------------------->-------------------------------------------------------------> HO DETECTION

PHYSICAL INFORMATION ----------------------------------><------------------------------------------------------------- start T3105stop T3124start T200------------------------ SABM ---------------------------> stop T3105<-------------------------- UA ----------------------------- ESTABLISH INDICATIONstop T200 ---------------------------------->

HANDOVER COMPLETE HO CMP stop T3103-------------------------------------------------------------> ----------------------------------> HO PERFORMED

------------------------>Release of old TCH MC652, MC656

Both SDCCH and TCH are counted together.


1.155

HO FAIL. CASES > Incoming internal HO failures:

Handover procedure from the target cell point of view

Handover Preparation: congestion: no RTCH available in the target cell

does not concern the outgoing side (serving cell point of view)BSS problem (no specific counter)

Handover Execution: radio problem: the MS fails to access the new channel

the reversion/drop discrimination concerns only the serving cellBSS problem (no specific counter)

4.2 Internal handover indicators per cell Incoming internal HO - failures


1.156

HO FAIL. CASES > Incoming internal HO fail: congestionMC551TCH+MC91SDCCH

4.2 Internal handover indicators per cell Incoming internal HO - congestion

MS Serving Cell Serving BSC MSC


--------------------------------------------------------------> MC830No free TCH

MC551MC91

If no free SDCCH

From B7, MC551 replaces MC51of B6.As the counting of the Abis-TCH congestion case is in restriction in B8:

MC51(B6) = MC551(B7)


1.157

HO FAIL. CASES > Incoming internal HO fail: MS access problem

4.2 Internal handover indicators per cell Incoming internal HO - radio failure


-----------------------> MEASUREMENT RESULT------------------------------------------------------------------------>


CHANNEL ACTIV ACK---------------------------------->


MC660SABM

-----------x T3103 expiry MC653

MS Serving cell Target Cell BSC


HANDOVER ACCESS MC660------------------------------------------------------------->-------------------------------------------------------------> HO DETECTION

PHYSICAL INFORMATION ----------------------------------><------------------------------------------------------------- start T3105

SABM-------------------------------------------------------------> ESTABLISH INDICATION

UA ----------------------------------><------------------------------------------------------------- stop T3105

HANDOVER COMPLETE----------------------------------------------------- - - - -X

SABM-----------------------> ESTABLISH INDICATION

UA ------------------------------------------------------------------------><-----------------------

HO FAILURE HANDOVER FAILURE-----------------------> ------------------------------------------------------------------------> MC653

Release of new channel

All incoming internal HO failures due to radio problems are counted in the same counter MC653. Both radio failures with Reversion Old Channel and radio drop are counted together.


1.158

HO FAIL. CASES > Incoming internal HO counters

4.2 Internal handover indicators per cell Incoming internal HO - counters

Request MC830


Attempt MC831

Radio (MS access problem) MC653BSS Pb MC831-MC652-MC653

Success MC652

Execution

Preparation

INCOMING INTERNAL Handover

REQUEST

CONGESTION

ATTEMPT

MS ACCESS PB

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure


1.159

4.2 Internal handover indicators per cell Incoming internal HO - indicators

SUCCESS

HO FAIL. CASES > Incoming internal HO indicators

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics INDICATORS > Incoming handover > Incoming Intra BSC

HOIBEFR: efficiency of the incoming internal HO executionHOIBCGR: rate of incoming internal HO failures due to congestionHOIBPFR: rate of incoming internal HO failures due to BSS during the preparation phaseHOIBFLRR: rate of incoming internal HO failures due to radio problemsHOIBFLBR: rate of incoming internal HO failures due to BSS during the execution phase


1.160

HO FAIL. CASES > Outgoing internal HO failures

Handover procedure from the serving cell point of view

Handover Preparation: congestion on the target cell (no specific counter on the serving cell)BSS problem (no specific counter)

Handover Execution: radio problem: the MS reverts to the old channelradio problem: the MS dropsBSS problem (no specific counter)

4.2 Internal handover indicators per cell Outgoing internal HO - failures


1.161

HO FAIL. CASES > Outgoing internal HO fail: reversionold channel

4.2 Internal handover indicators per cell Outgoing internal HO - radio failure ROC



HANDOVER ACCESS MC660------------------------------------------------------------->-------------------------------------------------------------> HO DETECTION



UA ----------------------------------><------------------------------------------------------------- stop T3105



UA ------------------------------------------------------------------------><-----------------------

HO FAILURE HANDOVER FAILURE-----------------------> ------------------------------------------------------------------------> MC657



1.162

HO FAIL. CASES > Outgoing internal HO fail: drop

clear_request: ask the MSC to release the connectionIn case of call drop due to HO, the cause is "radio interface message failure" (for Alcatel)


-----------------------> MEASUREMENT RESULT------------------------------------------------------------------------> MC655A


CHAN ACTIV ACK---------------------------------->


MC660SABM

----------xT3103 expiryMC658

Clear_request------------------------>

Clear_commandRelease of old and new TCH <------------------------

4.2 Internal handover indicators per cell Outgoing internal HO - radio failure drop


1.163

HO FAIL. CASES > Outgoing internal HO counters

4.2 Internal handover indicators per cell Outgoing internal HO - counters

Preparation Request MC655A

Any preparation failure MC655A-MC660

Attempt MC660


Success MC656

Execution

OUTGOING INTERNAL Handover

REQUEST

CONGESTION

ATTEMPT


DROP RADIO

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure


1.164

4.2 Internal handover indicators per cell Outgoing internal HO - indicators

SUCCESS

HO FAIL. CASES > Outgoing internal HO indicators

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics INDICATORS > Outgoing handover > Outgoing Intra BSC

HOOBRQR: efficiency of the outgoing internal HO preparation.HOOBEFR: efficiency of the outgoing internal HO execution.HOOBOCR: rate of outgoing internal HO failures due to radio problems with Reversion Old Channel.HOOBCDRR: rate of outgoing internal HO failures due to radio problems with drop.HOOBCDR: rate of incoming internal HO failures with drop (radio + BSS).




4.3 External handover indicators per cell


1.166

4.3 External handover indicators per cell External HO - success

HO FAIL. CASES > External HO > successful case

B8

MS serving_cell BSC MSC BSC target_cell MS- MEAS_REPORT ->

------- MEAS_RESULT -------->MC645A ------ HO_REQUIRED ---------->

----------CR (HO_REQUEST) -----> MC820<--------- CC ------------------------ ---- CHANNEL_ACTIVATION ------>

<- CHANNEL_ACT_ACK-------------<----- HO_REQUEST_ACK -------- Start T9113

(HO_COMMAND) MC821<------------------------- HO_COMMAND ------------------------------------------------------ <---- HO_ACCESS -----

MC650 Start T8 <---- HO_ACCESS -----<------ HO_DETECTION--------------

<-- HO_DETECTION -------------- --- PHYSICAL_INFO -->

<--- SABM ---------------<----- ESTABLISH_INDICATION ---- ----- UA -------------->

<----------- HO_COMPLETE ----------------------------------------<--- HO_COMPLETE --------------- Stop T9113

<---- CLEAR_COMMAND ------ MC642MC646 Cause : HO_SUCCESSFUL

Release of TCH Stop T8

MC462A

MC462B

MC462C

MC463A

MC463B

MC463C

(See comments)

Both SDCCH and TCH are counted together.From B7, MC645A replaces MC645 of B6.MC645a is only counting HANDOVER REQUIRED messages that are linked to a handover trial and not those that are linked to the update of the candidate cell list for handover / directed retry. This is leading to a more accurate computation of the External outgoing HO success rate.

B7.2: Only Outgoing inter PLMN HO is allowed but no counters.B8: 6 new counters provide information for "Inter-PLMN HO" (Incoming and Outgoing)

MC462a (equivalent of MC645A for intra PLMN external HO)Number of inter-PLMN TCH outgoing handovers or directed retry requests: HANDOVER REQUIRED sent to the MSC for an external TCH HO or an external DR triggered towards a cell belonging to a PLMN different from the PLMN of the serving cell.MC462b (equivalent of MC650 for intra PLMN external HO)Number of inter-PLMN TCH outgoing handovers or directed retry attempts: HANDOVER COMMAND sent to the MS on Abis for an external TCH HO or an external DR triggered towards a cell belonging to a PLMN different from the PLMN of the serving cell.MC462c (equivalent of MC646 for intra PLMN external HO)Number of inter-PLMN TCH outgoing handovers or directed retry successes: CLEAR COMMAND with Cause "Handover successful" received from the MSC for an external TCH HO or an external DR triggered towards a cell belonging to a PLMN different from the PLMN of the serving cell.MC463a (equivalent of MC820 for intra PLMN external HO)Number of inter-PLMN TCH incoming handovers or directed retry requests: HANDOVER REQUEST received from the MSC for an external TCH HO or an external DR triggered towards the target cell from a serving cell belonging to a PLMN different from the PLMN of the target cell.MC463b (equivalent of MC821 for intra PLMN external HO)Number of inter-PLMN TCH incoming handovers or directed retry attempts: HANDOVER REQUEST ACK sent by the target BSC containing the HANDOVER COMMAND for an external TCH HO or an external DR triggered towards the target cell from a serving cell belonging to a PLMN different from the PLMN of the target cell.MC463c (equivalent of MC642 for intra PLMN external HO)Number of inter-PLMN TCH incoming handovers or directed retry successes: HANDOVER COMPLETE received from the MS on Abis for an external TCH HO or an external DR triggered towards the target cell from a serving cell belonging to a PLMN different from the PLMN of the target cell.

Note than all other (previous) counters related to HO continue to be based on Intra PLMN only.


1.167

4.3 External handover indicators per cell External HO - failures

HO FAIL. CASES > Incoming external HO failures

Handover procedure from the target cell point of view

Handover Preparation: congestion: no RTCH available in the target cell OR no TTCH available on the A interface


Handover Execution: radio problem: the MS fails to access the new channel



1.168

4.3 External handover indicators per cell Incoming external HO - RTCH congestion

HO FAIL. CASES > Incoming external HO fail: Air/Abis cong.MC541ATCH+MC81SDCCH


------- MEAS_RESULT -------->MC645A ------ HO_REQUIRED ------->

----------CR (HO_REQUEST) -----> MC820

<----- HO_FAILURE --------------- MC541A( <-HO_REQUIRED_REJECT-) Cause: no radio resource available

From B7, MC541A replaces MC41A of B6.As the counting of the Abis-TCH congestion case is in restriction in B8:

MC41A(B6) = MC541A(B7)


1.169

4.3 External handover indicators per cell Incoming external HO - TTCH congestion

HO FAIL. CASES > Incoming external HO fail: A int. cong.MC41B


------- MEAS_RESULT -------->MC645A ------ HO_REQUIRED ------->

----------CR (HO_REQUEST) -----> MC820

<----- HO_FAILURE --------------- MC41BCause: terrestrial circuit already allocatedRequested terrestrial resource unaivalableBSS not equiopoed

( <-HO_REQUIRED_REJECT-)


1.170

HO FAIL. CASES > Incoming external HO fail: MS accessproblem

4.3 External handover indicators per cell Incoming external HO - radio failure


------- MEAS_RESULT -------->MC645A ---- HO_REQUIRED ------->

----------CR (HO_REQUEST) -------------------> MC820<-------- CC --------------------------------------- - CHANNEL_ACT ---------->

<--- CHA_ACT_ACK --------Start T9113

<----- HO_REQUEST_ACK----------------------- Start T9113<-------------------------- HO_COMMAND ------------------------------------------------ HO-COMMAND) included° MC821

Start T8 X --- HO_ACCESS -----X ---- HO_ACCESS -----

----- SABM --- X----- SABM --- X

----- SABM --- X T9113 expiryMC643

Release of connection



----------CR (HO_REQUEST) -------------------> MC820<-------- CC --------------------------------------- - CHANNEL_ACT ---------->

<--- CHA_ACT_ACK --------<----- HO_REQUEST_ACK----------------------- Start T9113 (HO-COMMAND) included MC821

<-------------------------- HO_COMMAND ------------------------------------------------Start T8 X --- HO_ACCESS -----

X ---- HO_ACCESS ---------- SABM --------><--- UA ------------- -- ESTABLISH_INDICATION->

----- HO_FAILURE (reversion to old channel) ------------------------------------------>----- CLEAR_COMMAND ----------------------> MC643Radio interface fail : Reversion to old channel Release of connection

All incoming external HO failures due to radio problems are counted in the same counter MC643. Both radio failures with Reversion Old Channel and radio drop are counted together.


1.171

HO FAIL. CASES > Incoming external HO counters

4.3 External handover indicators per cell Incoming external HO - counters

Request MC820


Attempt MC821

Radio (MS access problem) MC643BSS Pb MC821-MC642-MC643

Success MC642

Execution

Preparation

INCOMING EXTERNAL Handover

REQUEST

CONGESTION

ATTEMPT

MS ACCESS PB

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure

ATTEMPT SUCCESS

REQUEST

RATIO

Inter PLMN HO Intra PLMN HO

B8

New B8


1.172

4.3 External handover indicators per cell Incoming external HO - indicators

ATTEMPT

BSS PB

SUCCESS

HO FAIL. CASES > Incoming external HO indicators

B8 (See comments)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics INDICATORS > Incoming handover > Incoming Inter BSC

HOIMEFR: efficiency of the incoming external HO execution.HOIMCGR: rate of incoming external HO failures due to radio congestion (Air or Abis TCH).HOIMAMR: rate of incoming external HO failures due to CIC congestion (A TCH).HOIMPFR: rate of incoming external HO failures due to BSS during the preparation phase.HOIMFLRR: rate of incoming external HO failures due to radio problems.HOIMFLBR: rate of incoming external HO failures due to BSS during the execution phase.

B8: Inter PLMN Incoming External HO Indicators

An indicator is created for each new counter.REQUESTSATTEMPTSSUCCESS

In addition, new indicators show: the success rate of incoming inter-PLMN HOs,the ratio of incoming inter-PLMN HO to incoming intra-PLMN and inter-PLMN HO,


1.173

4.3 External handover indicators per cell Outgoing external HO - failures

HO FAIL. CASES > Outgoing external HO failures

Handover procedure from the serving cell point of view

Handover Preparation: congestion on the target cell (no specific counter on the serving cell)BSS problem (no specific counter)

Handover Execution: radio problem: the MS reverts to the old channelradio problem: the MS dropsBSS problem (no specific counter)


1.174

4.3 External handover indicators per cell Outgoing external HO - radio failure ROC

HO FAIL. CASES > Outgoing external HO fail: reversion old channel



----------CR (HO_REQUEST) -------------------><-------- CC --------------------------------------- - CHANNEL_ACT ---------->

<--- CHA_ACT_ACK --------<----- HO_REQUEST_ACK----------------------- Start T9113 (HO-COMMAND) included

<-------------------------- HO_COMMAND ------------------------------------------------Start T8 X --- HO_ACCESS -----MC650 X ---- HO_ACCESS -----

----- SABM --------><--- UA ------------- -- ESTABLISH_INDICATION->

----- HO_FAILURE (reversion to old channel) ------------------------------------------>MC647 ----- CLEAR_COMMAND ---------------------->

Radio interface fail : Reversion to old channelRelease of connection


1.175

4.3 External handover indicators per cell Outgoing external HO - radio failure drop

HO FAIL. CASES > Outgoing external HO fail: drop



----------CR (HO_REQUEST) -------------------><-------- CC --------------------------------------- - CHANNEL_ACT ---------->

<--- CHA_ACT_ACK --------<----- HO_REQUEST_ACK----------------------- Start T9113 (HO-COMMAND) included

<-------------------------- HO_COMMAND ------------------------------------------------Start T8 X --- HO_ACCESS -----MC650 X ---- HO_ACCESS -----

----- SABM --- X----- SABM --- X

----- SABM --- X

T8 expiry ----- CLEAR_REQUEST ->MC648 Radio interface message fail



1.176

HO FAIL. CASES > Outgoing external HO counters

4.3 External handover indicators per cell Outgoing external HO - counters

Preparation Request MC645A

Any preparation failure MC645A-MC650

Attempt MC650


Success MC646

Execution

OUTGOING EXTERNAL Handover

REQUEST

CONGESTION

ATTEMPT


DROP RADIO

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure

ATTEMPT SUCCESS

REQUEST

RATIO

Inter PLMN HO Intra PLMN HO

B8

New B8


1.177

4.3 External handover indicators per cell Outgoing external HO - indicators

ATTEMPT

SUCCESS

HO FAIL. CASES > Outgoing external HO indicators

B8 (See comments)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics INDICATORS > Outgoing handover > Outgoing Inter BSC

HOOMRQR: efficiency of the outgoing external HO preparation.HOOMEFR: efficiency of the outgoing external HO execution.HOOMOCR: rate of outgoing external HO failures due to radio problems with Reversion Old Channel.HOOMCDRR: rate of outgoing external HO failures due to radio problems with drop.HOOMCDR: rate of incoming external HO failures with drop (radio + BSS).

B8: Inter PLMN Outgoing External HO Indicators

An indicator is created for each new counter.REQUESTSATTEMPTSSUCCESS

In addition, new indicators show: the success rate of outgoing inter-PLMN HOs,the ratio of outgoing inter-PLMN HO to outgoing intra-PLMN and inter-PLMN HO.




4.4 Handover indicators per couple of cells


1.179

4.4 Handover indicators per couple of cells Type 180 counters

Some handover indicators available per couple of (serving, target) cells:

permanently for all adjacencies through PM type 180 counters 3 counters for each (Serving,Target)

adjacency: C400(S,T): Incoming handovers requested to cell T from cell SC401(S,T): Incoming handovers attempted to cell T from cell SC402(S,T): Incoming handovers successfully performed to cell T from cell S

both internal and external inter cell handovers are counted

both SDCCH and TCH handoversare counted

a

e

d

c

b

f

C40i(f,d)

C40i(a,b)C40i(c,b)

C40i(c,d)

According to the definition of C40i counters: ∑ C400(Sn,T) = MC820(T) + MC830(T)

∑ C401(Sn,T) = MC821(T) +MC831(T)

∑ C402(Sn,T) = MC642(T) + MC652(T)

where

Sn are the serving cells considering the incoming adjacencies to cell T.

MC820(T), MC821(T), MC642(T) are the counters relating to the incoming external handovers requested, attempted and successfully performed to cell T.

MC830(T), MC831(T), MC646(T) are the counters relating to the incoming internal handovers requested, attempted and successfully performed to cell T.

n

n

n


1.180

4.4 Handover indicators per couple of cells Type 180 indicators

The following indicators can be computed from PM Type 180 counters in order toDetect the most important neighboring cells as per their traffic

Distribution of incoming handovers performed to cell T from serving cells Sn

= C402(Sx,T) / ∑ C402(Sn,T)

Ease the diagnosis of the bad handover performance of a cell Global efficiency of incoming handovers to cell T from cell S

HOOASUR = C402(S,T) / C400(S,T)

Efficiency of the incoming handover preparation to cell T from cell SHOOACAR = C401(S,T) / C400(S,T)

Efficiency of the incoming handover execution to cell T from cell SHOOAEFR = C402(S,T) / C401(S,T)

n

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics > HO Statistics per couple of cells > Indicators with counter type 180

These indicators can also be to check if a recently handover relationship is generating handover as expected.They will also allow to identify the handover relationships which should be deleted since no (or very few) handover is observed.


1.181

counters for each (Serving,Target x) adjacency: C720(S,Tx): Outgoing handovers attempted from

cell S to cell TxC721(S,Tx): Outgoing handovers successfully

performed from cell S to cell TxC722(S,Tx): Outgoing handovers failed from cell

S to cell Tx with Reversion Old ChannelC723(S,Tx): Outgoing handovers failed from cell

S to cell Tx with drop

these type 26 counters are available for several cells at the same time (40 cells)


Some handover indicators are available per couple of (serving, target) cells:

on demand for all outgoing adjacencies of a serving cell through PM type 26

Target a

Te

Serving

Tc

Tb

Tf

C72i(S,Te)

C72i(S,Tc)

B8

Modified in B8

Other counters are provided: C724(S,Tx): Outgoing handovers attempted from S to Tx for an emergency cause.C725(S,Tx): Outgoing handovers attempted from S to Tx for a better cell cause.C727(S,Tx): Outgoing handovers attempted from S to Tx for a traffic cause.C728(S,Tx): Outgoing handovers attempted from S to Tx for a forced directed retry cause.

Previously the set of Type 26 counters could be retrieved for only one cell per BSS at once.40 cells at the same time in B8.


1.182


The following indicators can be computed from PM Type 26 counters in order to:ease the diagnosis of the bad outgoing handover performance of acell

Efficiency of the outgoing handover execution from cell S to cell TxHOOXSUR = C721(S,Tx) / C720(S,Tx)Rate of outgoing ho execution failures due to radio problems from S to Txwith dropHOOXCDRR = C723(S,Tx) / C720(S,Tx)Rate of outgoing ho execution failures due to radio problems from S to Txwith Reversion Old ChannelHOOXOCR = C722(S,Tx) / C720(S,Tx)Rate of outgoing ho execution failures due to BSS problems from S to TxHOOXCDBR = [C720(S,Tx)-C721(S,Tx)-C722(S,Tx)-C723(S,Tx)] / C720(S,Tx)

these type 26 counters are available for several cells at once (40 cells)

B8

Modified in B8

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics > HO Statistics per couple of cells > Indicators with counter type 26.In B8, these type 26 counters are available for several cells at once (40 cells).


1.183

counters for each (Serving,Target x) adjacency:

C730(Sx,T): Incoming handovers attempted to cell T from cell Sx

C731(Sx,T): Incoming handovers successfully performed to cell T from cell Sx

C733(S,Tx): Incoming handovers failed due to MS radio access problems to cell T from cell Sx


Some handover indicators are available per couple of (serving, target) cells:

on demand for all incoming adjacencies of a target cell through PM type 27

Serving a

Se

Target

Sc

Sb

Sf

C73i(Se,T)

C73i(Sc,T)

Other counters are provided: C734(Sx,T): Incoming handovers attempted from Sx to T for an emergency cause.C735(Sx,T): Incoming handovers attempted from Sx to T for a better cell cause.C737(Sx,T): Incoming handovers attempted from Sx to T for a traffic cause.C738(Sx,T): Incoming handovers attempted from Sx to T for a forced directed retry cause.

The set of Type 27 counters can be retrieved for only one cell per BSS at once.


1.184


The following indicators can be computed from PM Type 27 counters in order toEase the diagnosis of the bad incoming handover performance of a cell

Efficiency of the incoming handover execution to cell T from cell SxHOIXSUR = C731(Sx,T) / C730(Sx,T)

Rate of incoming ho execution failures due to MS radio access problems to cell T from cell Sx

HOIXCDRR = C733(Sx,T) / C730(Sx,T)

Rate of incoming ho execution failures due to BSS problems to cell T from cell Sx

HOIXCDBR= [C730(Sx,T)-C731(Sx,T)-C733(Sx,T)] / C730(Sx,T)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Handover Statistics > HO Statistics per couple of cells > Indicators with counter type 27



5 DIRECTED RETRY INDICATORS


1.186

5 Directed retry indicatorsSession presentation

Objective: to be able to describe the counters and indicators used for monitoring the efficiency of the directed retry feature

Program: 5.1 Internal directed retry indicators5.2 External directed retry indicators




5.1 Internal directed retry indicators


1.188

5.1 Internal directed retry indicators Queuing on TCH assignment

When there is no TCH available in a cell for TCH normal assignment:

Queuing: TCH request is put in a queue, waiting for a TCH to be released in this cell

With default BSS tuning: the call establishment fails if no TCH has been freed after T11 seconds

but an optional mechanism can be activated

The queuing of TCH requests is also performed for incoming external TCH handovers but not for incoming internal TCH handovers.


1.189

5.1 Internal directed retry indicators Directed retry definition

Directed Retry (DR): When a TCH request is in queue, the BSC tries to establish the TCH connection on a neighboring cell if:

the normal handover condition is met (Normal DR)

specific directed retry conditions are met (Forced DR): the MS receives a sufficient signal level from a neighboring cell

the number of free TCHs in this neighboring cell is sufficient


1.190

5.1 Internal directed retry indicators Directed retry types

DR FAIL. CASES > DR ReminderDR as an SDCCH to TCH handover can be

Internalbetween two cells of the same BSCalso called intra BSC

Externalbetween two cells of different BSCsalso called inter BSC

Incomingas considering the target cell

Outgoingas considering the serving cell

Synchronousbetween 2 cellssharing the same clockscollocatedusually 2 sectors of the same BTS

tunable at OMC-R levelAsynchronous

not synchronous for any reasonno dedicated monitoring for synchronous/asynchronous HO


1.191

DR FAIL. CASES > internal DR > success case

5.1 Internal directed retry indicators Internal DR - success

The same internal DR procedure leads to an incrementation of two sets of counters: incoming DR counters for the target cell: MC153, MC151, etc.outgoing DR counters for the serving cell: MC144E, MC142E, etc.

MCx counters belong to Standard Type 110 reported permanentlyCx counters belong to Detailed Type 29 reported on demand in B7.

Becomes a Standard type in B8.

MS serving cell target cell BSC MSCTCH ASSIGNMENT PHASE (OC or TC)

< -----------------------ASSIGNMENT

REQUESTNo free TCH

TCH request queuedQueuing allowed

Start T11 ----------------------- >QUEUING_INDIC.

MC13A

IDR condition met MC153, MC144e,

CHANNEL ACTIV. (TCH)<---------------------------------- MC15A

CHAN ACTIV ACK---------------------------------->

HO CMD HANDOVER COMMAND<----------------------

(SDCCH)<------------------------------------------------------------------------ start T3103

C154, MC607start T3124 C145A+C145C

HANDOVER ACCESS------------------------(TCH)---------------------------->-------------------------------------------------------------> HO DETECTION

PHYSICAL INFORMATION ----------------------------------><------------------------------------------------------------- start T3105stop T3124start T200------------------------ SABM --------------------------> stop T3105<-------------------------- UA ----------------------------- ESTABLISH INDICATIONstop T200 ---------------------------------->

HANDOVER COMPLETE HO CMP stop T3103-------------------------------------------------------------> ----------------------------------> ASSIGNMENT

COMPLETE------------------------>

Release of old SDCCH MC151,MC717A,MC142e

B8 (see comments)

Modified inB8

The following DR counters are provided in Type 110for the target cell:

MC13A: TCH requests for Normal Assignment that are put into the queue,MC153: incoming internal DR requests,MC15A: TCH allocations for incoming internal DR,MC151: incoming internal DR successes per cell,MC717A: incoming internal DR successes per TRX.

for the serving cell: MC144E: outgoing internal DR requests,MC142E: outgoing internal DR successes,MC607: outgoing internal+external DR attempts.

The following DR counters are provided in Type 29 (this type becomes a standard type in B8)for the target cell:

C153: incoming internal DR requests,C154: incoming internal DR attempts,C151: incoming internal DR successes.

for the serving cell: C144A: forced outgoing internal DR requests,C144C: normal outgoing internal DR requests,C145A: forced outgoing internal DR attempts,C145C: normal outgoing internal DR attempts,C142A: forced outgoing internal DR successes,C142C: normal outgoing internal DR successes.

All the counters here and in the next slides concerning directed retry and relative to type 29 can be activated for all cells of the BSC at once from B8. (Type 29 becomes a standard type in B8):

C142a, C142b, C142c, C142d, C143a, C143b, C143c, C143d, C143e, C143f, C143g, C143h, C144a, C144b, C144c, C144d, C145a, C145b, C145c, C145d, C151, C152,C153, C154, C555


1.192

DR FAIL. CASES > Incoming internal DR failures:

Directed Retry procedure from the target cell point of view

DR Preparation: congestion: no RTCH available in the target cell


DR Execution: radio problem: the MS fails to access the new channel


5.1 Internal directed retry indicators Incoming internal DR - failures


1.193

DR FAIL. CASES > Incoming internal DR fail: congestionMC555=C155

5.1 Internal directed retry indicators Incoming internal DR - congestion

MS serving cell target cell BSC MSCTCH ASSIGNMENT PHASE (OC or TC)

< ----------------------------------------------------ASSIGNMENT REQUEST

No free TCHIn serving cell

Queuing allowed

Start T11 --------------------------------------------------- >QUEUING_INDIC.

MC13A

IDR condition met MC153, MC144e,MC607

No free TCHIn target cell

MC555

B8 (see comments)

type 29 becomes

a standard type:

Available in PMC

C155 is available in Type 29. (Standard type in B8)


1.194

DR FAIL. CASES > Incoming internal DR fail: MS access problem

5.1 Internal directed retry indicators Incoming internal DR - radio failure


-----------------------> MEASUREMENT RESULT------------------------------------------------------------------------>


CHANNEL ACTIV ACK---------------------------------->


C154SABM

-----------x T3103 expiry C152



HANDOVER ACCESS C154------------------------------------------------------------->-------------------------------------------------------------> HO DETECTION



UA ----------------------------------><------------------------------------------------------------- stop T3105



UA ------------------------------------------------------------------------><-----------------------

HO FAILURE HANDOVER FAILURE-----------------------> ------------------------------------------------------------------------> C152


B8 (see comments)

Modified inB8 Becomes a standard type

All incoming internal DR failures due to radio problems are counted in the same counter C152. This counter is provided in Type 29 (this type becomes a standard type in B8).Both radio failures with Reversion Old SDCCH Channel and radio drop are counted together.


1.195

DR FAIL. CASES > Incoming internal DR counters

5.1 Internal directed retry indicators Incoming internal DR - counters

Request MC153, C153

Congestion MC555, C155BSS Pb C153-C154-C155

Attempt C154

Radio (MS access problem) C152BSS Pb C154-C151-C152

Success MC151, C151

Execution

Preparation

INCOMING INTERNAL Directed Retry

REQUEST

CONGESTION

ATTEMPT

MS ACCESS PB

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure

B8 (see comments)

Modified inB8

Type 29 counters becomes a standard (PMC)

All MCxxx counters are available in Type 110.All Cxxx counters are available in Type 29.Type 29 counters becomes a standard in B8.


Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Specific indicators for densification techniques > Directed Retry > Incoming DR

DRIBCAR: efficiency of the incoming internal DR preparation = MC15A/MC153DRIBCNR: rate of incoming internal DR failures due to congestion = MC155/MC153DRIBEFR: efficiency of the incoming internal DR execution = MC717A/MC153

Other indicators can be computed from Type 110 counters:

DRIBSUR: global efficiency of incoming internal DR = MC717A/MC153 = MC151/MC153

from Type 29 counters: (Type 29 becomes a standard type in B8)

rate of incoming internal DR preparation failures due to BSS problems = (C153-C154-C155)/C153rate of incoming internal DR execution failures due to BSS problems = (C154-C151-C152)/C154rate of incoming internal DR execution failures due to radio access problems = C152/C154


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DR FAIL. CASES > Outgoing internal DR failures

Directed Retry procedure from the serving cell point of view

DR Preparation: congestion on the target cell (no specific counter on the serving cell)BSS problem (no specific counter)

DR Execution: radio problem: the MS reverts to the old channelradio problem: the MS dropsBSS problem (no specific counter)

5.1 Internal directed retry indicators Outgoing internal DR - failures


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DR FAIL. CASES > Outgoing internal DR fail: reversionold channel

C144A, C143A: Forced DR

C144C,C143E: Normal DR

5.1 Internal directed retry indicators Outgoing internal DR - radio failure ROC


HO CMD HANDOVER COMMAND<-------SDCCH----- <------------------------------------------------------------------------ start T3103

HANDOVER ACCESS MC144E----------------------TCH--------------------------------> C144A or C144C-------------------------------------------------------------> HO DETECTION



UA ----------------------------------><------------------------------------------------------------- stop T3105



UA ------------------------------------------------------------------------><-----------------------

HO FAILURE HANDOVER FAILURE-----------------------> ------------------------------------------------------------------------> C143A or C143E


B8 (see comments)

Type 29 counters becomes a standard in B8.


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DR FAIL. CASES > Outgoing internal DR fail: drop

M S serving ce ll ta rge t ce ll B S C M S C

H O C M D H A N D O V E R C O M M A N D<----------------------- <------------------------------------------------------------------------ start T 3103

M C 144ES A B M C 144A or C 144C

----------x

T 3103 exp iryC 143B o r C 143F------------------------>

A S S IG N M E N TFAILU R E

“R ad io in te rfacem essage fa ilu re ”

R elease o f S D C C H and TC H

5.1 Internal directed retry indicators Outgoing internal DR - radio failure drop

C144A,C143B: Forced DR

C144C,C143F: Normal DR

(See comments)B8

Counters C144A, C143B, C144C, C143F are type 29.Type 29 becomes a standard type in B8.


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DR FAIL. CASES > Outgoing internal DR counters

5.1 Internal directed retry indicators Outgoing internal DR - counters

Preparation Request MC144E, C144A+C144C

Any preparation failure (C144A+C144C) - (C145A+C145C)

Attempt C145A+C145C

Reversion old channel C143A+C143EDrop radio C143B+C143FBSS Pb (C145A+C145C) - (C143A+C143E+C143B+C143F)

Success MC142E, C142A+C142C

Execution

OUTGOING INTERNAL Directed Retry

REQUEST

CONGESTION

ATTEMPT


DROP RADIO

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure

(See comments)B8

Modified in B8

Detailed Pb available in standard type

B8: Pb details available in PMC (type 29 becoming standard)


Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Specific indicators for densification techniques > Directed Retry > Outgoing DR

DROBSUR: global efficiency of outgoing internal DR = MC142E/MC144E

Other indicators can be computedfrom Type 29 counters:

efficiency of the outgoing internal DR preparation = (C145A+C145C)/(C144A+C144C)efficiency of the outgoing internal DR execution = (C142A+C142C)/(C145A+C145C)rate of outgoing internal DR execution failures due to BSS problems = [(C145A+C145C) - (C143A+C143E+C143B+C143F)] / (C145A+C145C)rate of outgoing internal DR execution failures due to radio problems with reversion old channel = (C143A+C143E) / (C145A+C145C)rate of outgoing internal DR execution failures due to radio problems with drop = (C143B+C143F) / (C145A+C145C)

In B8, as Type 29 becomes a standard, 10 new stored indicators based on type 29 counters are defined:

DRFOSUIN C142a NB_OUT_FORCED_IDR_SUCC DRFOSUEN C142b NB_OUT_FORCED_EDR_SUCCDROBSUIN C142c NB_OUT_NOR_IDR_SUCCDROMSUEN C142d NB_OUT_NOR_EDR_SUCCDRFORDIN C144a NB_OUT_FORCED_IDR_REQDRFORDEN C144b NB_OUT_FORCED_EDR_REQDROBRDIN C144c NB_OUT_NOR_IDR_REQDROMRDEN C144d NB_OUT_NOR_EDR_REQDROBRQIN C145c NB_OUT_NOR_IDR_ATPTDROMRQEN C145d NB_OUT_NOR_EDR_ATPT

Type 29 counters becomes a standard in B8.




5.2 External directed retry indicators


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5.1 External directed retry indicators External DR - success

DR FAIL. CASES > External DR > successful case

MS serving_cell BSC MSC BSC target_cell MSTCH request queued <------ASSIGNT REQUEST-------

EDR condition met ------ HO_REQUIRED ---------->MC144F ----------CR (HO_REQUEST) -----> MC820

<--------- CC ------------------------ ---- CHANNEL_ACTIVATION ------><- CHANNEL_ACT_ACK-------------

<----- HO_REQUEST_ACK -------- Start T9113(HO_COMMAND) MC821

<------------------------- HO_COMMAND ------------------------------------------------------ <---- HO_ACCESS -----C145B+C145D Start T8 <---- HO_ACCESS -----

<------ HO_DETECTION--------------<-- HO_DETECTION -------------- --- PHYSICAL_INFO -->

<--- SABM ---------------<----- ESTABLISH_INDICATION ---- ----- UA -------------->

<----------- HO_COMPLETE ----------------------------------------<--- HO_COMPLETE --------------- Stop T9113

<---- CLEAR_COMMAND ------ MC642MC142F Cause : HO_SUCCESSFUL

Release of SDCCH Stop T8

The same external DR procedure leads to an incrementation of two sets of counters: incoming external HO counters for the target cell: MC820, MC821, etc.outgoing external DR counters for the serving cell: MC144F, MC142F, etc.

B8 (see comments)

The following DR counters are provided in Type 110for the serving cell:

MC144F: outgoing external DR requests,MC142F: outgoing external DR successes.

The following DR counters are provided in Type 29for the serving cell:

C144B: forced outgoing external DR requests,C144D: normal outgoing external DR requests,C145B: forced outgoing external DR attempts,C145D: normal outgoing external DR attempts,C142B: forced outgoing external DR successes,C142D: normal outgoing external DR successes.

As for internal DR, external DR Counters are available permanently (Type 29 becomes a standard type in B8)

No counter is provided for the target cell for an external DR since an incoming DR cannot always be discriminated from an incoming external HO. Therefore incoming external DRs are counted together with incoming external HOs in the related counters.


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5.1 External directed retry indicators Outgoing external DR - failures

DR FAIL. CASES > Outgoing external DR failures

Directed Retry procedure from the serving cell point of view

DR Preparation: congestion on the target cell (no specific counter on the serving cell)BSS problem (no specific counter)

DR Execution: radio problem: the MS reverts to the old channelradio problem: the MS dropsBSS problem (no specific counter)


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5.1 External directed retry indicators Outgoing external DR - radio failure ROC

DR FAIL. CASES > Outgoing external DR fail: reversionold channel

MS serving_cell BSC MSC BSC target_cell MSASSIGNT REQUEST---------------------> TCH request queued

EDR condition met ---- HO_REQUIRED ------->MC144F ----------CR (HO_REQUEST) ------------------->

<-------- CC --------------------------------------- - CHANNEL_ACT ----------><--- CHA_ACT_ACK --------

<----- HO_REQUEST_ACK----------------------- Start T9113 (HO-COMMAND) included


C145B+C145D X ---- HO_ACCESS ---------- SABM --------><--- UA ------------- -- ESTABLISH_INDICATION->

----- HO_FAILURE (reversion to old channel) ------------------------------------------>C143C+C143G ----- CLEAR_COMMAND ---------------------->

Radio interface fail : Reversion to old channel Release of connection

C145B,C143C: Forced DR

C145D,C143G: Normal DR


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5.1 External directed retry indicators Outgoing external DR - radio failure drop

DR FAIL. CASES > Outgoing external DR fail: drop

MS serving_cell BSC MSC BSC target_cell MSASSIGNT REQUEST---------------------> TCH request queued

EDR condition met ---- HO_REQUIRED ------->MC144F ----------CR (HO_REQUEST) ------------------->

<-------- CC --------------------------------------- - CHANNEL_ACT ----------><--- CHA_ACT_ACK --------

<----- HO_REQUEST_ACK----------------------- Start T9113 (HO-COMMAND) included


C145B+C145D X ---- HO_ACCESS ---------- SABM --- X----- SABM --- X

----- SABM --- X

T8 expiry ----- CLEAR_REQUEST ->C143D+C143H Radio interface message fail



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DR FAIL. CASES > Outgoing external DR counters

5.1 External directed retry indicators Outgoing external DR - counters

Preparation Request MC144F, C144B+C144D

Any preparation failure (C144B+C144D) - (C145B+C145D)

Attempt C145B+C145D

Reversion old channel C143C+C143GDrop radio C143D+C143HBSS Pb (C145+C145D) - (C143C+C143G+C143D+C143H)

Success MC142F, C142B+C142D

Execution

OUTGOING EXTERNAL Directed Retry

REQUEST

CONGESTION

ATTEMPT


DROP RADIO

BSS PB

SUCCESS

BSS PB

Preparation Failure

Execution Failure


Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Specific indicators for densification techniques > Directed Retry > Outgoing DR

DROMSUR: global efficiency of outgoing external DR = MC142F/MC144F

Other indicators can be computedfrom Type 29 counters:

efficiency of the outgoing internal DR preparation = (C145B+C145D)/(C144B+C144D)efficiency of the outgoing internal DR execution = (C142B+C142D)/(C145B+C145D)rate of outgoing internal DR execution failures due to BSS problems = [(C145B+C145D) - (C143C+C143G+C143D+C143H)] / (C145B+C145D)rate of outgoing internal DR execution failures due to radio problems with reversion old channel = (C143C+C143G) / (C145B+C145D)rate of outgoing internal DR execution failures due to radio problems with drop = (C143D+C143H) / (C145B+C145D)

Interesting indicator: TCQUSUDSR: rate of outgoing internal and external directed retries (forced + normal) successfully performed over all RTCH requests queued during normal assignment.



6 RADIO MEASUREMENT STATISTICS INDICATORS


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6 Radio Measurement Statistics indicatorsSession presentation

Objective: to be able to describe the RMS indicators used for radio quality assessment of a TRX or cell and to use them in thedetection of some typical radio problemsProgram:

6.1 Radio Measurement Statistics objectives6.2 RMS implementation in the BSS6.3 RMS data6.4 Call quality statistics per TRX6.5 Radio quality statistics per TRX6.6 C/I statistics6.7 RMS indicators usage6.8 Additional information




6.1 Radio Measurement Statistics objectives


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6.1 Radio Measurement Statistics objectivesRMS objectives

RMS objectivesAssess the quality of cell coverageAssess the radio link quality of a TRX / a cellAssess Carrier/Interference ratio of a TRX / a cellEstimate of the voice quality of a TRX / a cell

In order to: Optimize the neighborhood & frequency planningImprove the network coverageDetect faulty hardware components responsible for bad QoSHelp logical parameters fine tuning

The RMS feature provides statistics on Voice Quality. VQ data are now needed since the Call Drop rate is not sufficient to have a clear picture of the QoS in a network using Slow Frequency Hopping as a densification technique.

The RMS feature is a "plus" providing additional information to help radio engineer in their Fault detection and Network optimization tasks.


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6.1 Radio Measurement Statistics objectivesRMS objectives

RMS objectives

Provide Radio Measurement Statistics On all the network elements (all TRXs/cells)Permanently (RMS results available every day)

In order to Reduce the cost of Radio Network Optimization

Today's solutions for Radio Measurements are limited and very expensive: drive tests: provide a mobile user with the perception of the network but cannot be done on the whole network and on an

very day basis since:they are costly (tool+car+manpower).they need to be post-processed.they are limited to part of the network.they are available on the DownLink path only.

Abis interface traces: provide a complete Uplink and Downlink radio quality assessment of a cell but cannot be done on the whole network and on an every day basis since:

they are costly (protocol analyzer+manpower).they need to be post-processed.they are limited to a few cells at once per analyzer.




6.2 RMS implementation in the BSS


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6.2 RMS implementation in the BSSRMS management

RMS results are reported permanently (once a day) by the BSS as new PM counters to the OMC-R

The RMS job is defined and activated on a per BSS basis

RMS job parameters are managed through RMS templates

RMS templates provide means to tune RMS parameters according to Cell Planning (cell profile, cell class)

The cell profile can be: micro, indoor, multiband, etc.The cell class can be: rural, urban, rural rapid (covering express railway), etc.Templates parameters define the intervals or Received level, Consecutive frame erasure, Radio link counter, Path balance, C/I …for which RMS counters are provided.


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6.2 RMS implementation in the BSSRMS configuration in the OMC-R

PM

RMS in binary filesTemplatesTemplates

RMS with OMC-R only

Templates are defined on the OMC-R

RMS results are retrieved once a day from the BSC

Binary files can be exported for post-processing


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6.2 RMS implementation in the BSSRMS configuration in RNO

RMS with OMC-R, NPA & RNOTemplates are defined on RNO

RMS results are retrieved once a day from the BSC

Binary files are transferred to NPA

RMS warnings on NPARMS QoS reports on RNORMS reports used in RNO

CheckQoS follow-upDiagnosisTuning

The Experience matrix can be generated for network planningExcel export is adapted to RMS

Benefit to whole RNO

Templates

PMComputeexperience

matrix

The cell profile can be: micro, indoor, multiband, etc.The cell class can be: rural, urban, rural rapid (covering express railway), etc.


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6.2 RMS implementation in the BSSRMS data flow

RNO defines and sends RMS templates to the OMC-RThe OMC-R activates an RMS campaignin the BSSRMS counters are transferred tothe OMCRMS counters are stored in NPA RMS indicators requested by RNORMS QOS reportdisplayedRNO calculates and exports the Experience matrix to RNP

1

2

3

4

5

A9156 RNO

NPA

RNP

OMC-R

BSS

Template

1

Experience matrix

7

PM4

7

2PM

3

6

5QOS

6

QOS

RNO is able to define the templates for the RMS jobs and helps in defining the MAFA frequencies.The tuning function of RNO defines a preferred RMS template depending on cell characteristics (type, class, capacity, etc.).RNO manages the frequencies to monitor through MAFA jobs depending on the neighborhood and the frequency bands.

RNO is a reference for RMS templates:16 templates stored in the RNO database,Reference values for templates available,Extra editor in the administration tool to modify templates:

a given value or a reference one.

NPANPA stores RMS jobs measurements, at Cell & TRX levels (15 days).NPA makes some consolidations (voice quality, averages, etc.).NPA manages some warnings on RMS indicators (path balance).

The Experience Matrix generated by RNO is an interference matrix computed from C/I measurements provided through RMS counters.


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In all this chapter

System parameters (user tunable or not) will always be written in BLUE BOLD FONT

Indicators and counters will be typedin ITALIC and SHADOW EFFECT FONTITALIC and SHADOW EFFECT FONT

The light blue font highlights important points

6.2 RMS implementation in the BSSRMS data presentation




6.3 RMS data


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3 main RMS statistics types

Call quality statistics which qualify calls according to coverage/interference criteria

based on samples corresponding to measurement results averaged over a number of SACCH multi-frames

Radio statistics:

UL/DL level, UL/DL qual,

CFE

C/I statistics on neighboring freq/MAFA freq

last 2 statistics types based on samples corresponding to measurement results

6.3 RMS dataRMS data presentation

Annex 1

The first RMS Statistics type is based on calls.The two others are based on TRX/Cell.

additional informationMeasurement results, TRX, BS/MS max power

MAFA = Mobile Assisted Frequency Allocation is a GSM Phase 2+ feature allowing to request a mobile to measure and report through Extended Measurement Report message a C/I value for each frequency specified in an Extended Measurement Order message.

CFE: Consecutive Frame Erasure

1 SACCH multi-frame (SACCH mfr) corresponds to 4 consecutive sequences of 26 TDMA frames during which, in the uplink, a measurement report message is received by the BTS from the MS.




6.4 Call quality statistics per TRX





6.4.1 Generalities


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6.4.1 GeneralitiesVoice Quality problem

Suspecting a Voice Quality problemPercentage of Noisy calls

The fact that FER measurements are more reliable than RXQUAL ones to assess the VQ is even more true when using Slow Frequency Hopping. In this case RXQUAL values are not anymore correlated to Voice Quality as perceived by the end user.FER measurements are available for the uplink path only.These RMS indicators are provided on the RNO tool per TRX, per Cell:

Number of Noisy calls suffering from problem of bad coverage on the uplink pathRMVQULVN = RMS_call_noisy_UL_bad_coverageNumber of Noisy calls suffering from problem of interference on the uplink pathRMVQUIFN = RMS_call_noisy_UL_interferenceNumber of Noisy calls suffering from problem of interference and bad coverage considered together on the uplink pathRMVQUUKN = RMS_call_noisy_UL_undefinedRate of Noisy calls suffering from problems of interference or/and bad coverage on the uplink pathRMVQUNOR = RMS_call_noisy_UL_rate

Note: The 4 indicators above can be provided for Noisy calls suffering from VQ problems on the dowlink path.Rate of Noisy calls but with good FER measurements on the uplink pathRMVQFEGR = RMS_call_noisy_good_FER_rateRate of Noisy calls and also with bad FER measurements on the uplink pathRMVQFEBR = RMS_call_noisy_bad_FER_rateRate of calls with fair quality measurements but with bad FER measurements on the uplink pathRMVQFEAR = RMS_call_abnormal_bad_FER_rate

This last indicator can be used in order to tune the RMS VQ parameters used to characterize a call as Noisy.


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6.4.1 GeneralitiesCall Quality measurements

VQ_AVERAGE = 4 SACCH

AV_RXLEV_UL_VQ = (RxlevUL1+RxlevUL2+RxlevUL3+RxlevUL4) / 4AV_RXLEV_DL_VQ = (RxlevDL1+RxlevDL2+RxlevDL3+RxlevDL4) / 4

AV_RXQUAL_UL_VQ = (RxqualUL1+RxqualUL2+RxqualUL3+RxqualUL4) / 4AV_RXQUAL_DL_VQ = (RxqualDL1+RxqualDL2+RxqualDL3+RxqualDL4) / 4

AV_RXFER_UL_VQ = (Nb of speech frames wrongly decoded (BFI=1)/ Total nb of speech frames of the CQS)

Average level, quality and FER of a Call Quality Sample

SACCH meas.begin end

CALL

480ms

CQS1 CQS2 CQS3 CQS4 CQS5 CQS6 CQS7 CQS8 CQS9 CQS10 CQS11 CQS12 CQS13 CQS14 CQS15 CQS16 CQS375

1 measurement report⇔

1 SACCH mfr

CQS: Call Quality Sample

VQ_AVERAGE = Number of consecutive SACCH measurements from which the reported Level and Quality notes (UL and DL) are averaged. The resulting averages represent the level and quality of the corresponding Call Quality Sample, i.e. the portion of the call over which level and quality have been measured.

AV_RXLEV_xx_VQ = Average xx level measured over a Call Quality Sample (VQ_AVERAGE SACCH)

AV_RXQUAL_xx_VQ = Average xx quality measured over a Call Quality Sample (VQ_AVERAGE SACCH)


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6.4.1 GeneralitiesClassification of a CQS and Noisy Call identification

quality

Level (dBm)

7

0

-110 -47VQ_RXLEV

bad quality + good level

interfered CQS

bad quality & level

bad coverage CQS

VQ_RXQUAL

CQS

How to qualify the quality of a call? By looking at the repartition of the CQS!!:

VQ_RXLEV = radio level threshold to classify a CQS as bad coverage CQS.VQ_RXQUAL = radio quality threshold to classify a CQS as bad coverage CQS.VQ_INTF_THRESHOLD = Ratio of bad CQS (interference or bad coverage) to classify a Call as Noisy.A call is classify as:

Noisy xx Interference if Ratio of xx interfered CQS > VQ_INTF_THRESHOLD Noisy xx Coverage if Ratio of xx bad coverage CQS > VQ_INTF_THRESHOLDNoisy xx Undefined if Ratio of (xx interfered CQS + xx bad coverage CQS) > VQ_INTF_THRESHOLD





6.4.2 Call quality parameters


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6.4.2 Call quality parametersRMS parameters

Call quality statisticsParameters used to determine if a call is noisy (according to

RXQUAL) and of bad voice quality (according to FER)

VQ_AVERAGE: averaging window size on measurement results to obtain Call Quality Samples (CQSs) (0 SACCH mfr to 128 Smf)

VQ_RXLEV: radio level threshold to specify a bad coverage CQS for noisy call statistics (-110 to -65 dBm)

VQ_RXQUAL: radio quality threshold to specify a bad quality (RXQUAL) CQS for noisy call statistics (0 to 7)

VQ_RXQUAL_VS_RXFER: radio quality threshold to specify a bad or a good quality CQS correlated to bad or good FER measurements for noisy call statistics (0 to 7)

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpc = PAR_VQ_AVERAGERMSpd = PAR_VQ_RXLEVRMSpe = PAR_VQ_RXQUALRMSpf = PAR_VQ_RXQUAL_VS_RXFER

Call Quality Sample (A CQS) will be qualified as “of bad level” if the Average RxLevel is lower than VQ_RXLEVA CQS will be qualified as “of bad quality” if the Average RxQuality is greater than VQ_RXQUAL

For FER counters, VQ_RXQUAL_VS_RXFER is used instead of VQ_RXQUAL to qualify a CQS as “of bad quality” if the Average FER is also checked (compared to VQ_xx_RXFER).

Note: For CQS, the averaging process is non-sliding.


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6.4.2 Call quality parametersRMS parameters

call quality statistics

VQ_GOOD_RXFER: Frame Erasure Rate threshold to specify a good FER CQS for noisy call statistics (0 to 20%)

VQ_BAD_RXFER: FER threshold to specify a bad FER CQS for noisy call statistics (0 to 20%)

VQ_INTF_THRESHOLD: Call Quality Samples threshold to characterize a call as noisy (0 to 100%)

VQ_FER_THRESHOLD: Call Quality Samples threshold to characterize a call as “of bad or good” voice quality (0 to 100%)

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpg = PAR_VQ_GOOD_RXFERRMSph = PAR_VQ_ BAD_RXFERRMSpi = PAR_VQ_INTF_THRESHOLDRMSpj = PAR_VQ_FER_THRESHOLD





6.4.3 Call quality counters


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6.4.3 Call quality countersRMS counters (1/4)

VQ_NOISY_UL_INTERFERENCEVQ_NOISY_UL_INTERFERENCERMS10 = Number of calls suffering from interference problem on the uplink path

VQ_NOISY_UL_INTERFERENCEVQ_NOISY_UL_INTERFERENCE is incremented whenever a call verifies: 100*(INTERFERED_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLD

with INTERFERED_UL_SAMPLES = nb of times where AV_RXQUAL_UL_VQ > VQ_RXQUALand AV_RXLEV_UL_VQ>VQ_RXLEV

Call Quality Statistics counters are related only to speech channels.

Considering:AV_RXQUAL_UL_VQ: average on VQ_AVERAGE measurements of RXQUAL_ULAV_RXLEV_UL_VQ: average on VQ_AVERAGE measurements of RXLEV_ULNUM_UL_SAMPLES: total number of averages calculated on UL measurements during the call on the considered TRX


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VQ_NOISY_UL_INTERFERENCEVQ_NOISY_UL_INTERFERENCERMS10 = Number of calls suffering from interference problem on the uplink pathVQ_NOISY_DL_INTERFERENCEVQ_NOISY_DL_INTERFERENCERMS11 = Number of calls suffering from interference problem on the downlink pathVQ_NOISY_UL_COVERAGEVQ_NOISY_UL_COVERAGERMS12 = Number of calls suffering from bad coverage problem on the uplink pathVQ_NOISY_DL_COVERAGEVQ_NOISY_DL_COVERAGERMS13 = Number of calls suffering from bad coverage problem on the downlink path


RMS10 = VQ_NOISY_UL_INTERFERENCE is incremented whenever a call verifies: 100*(INTERFERED_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLD

with INTERFERED_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL and AV_RXLEV_UL_VQ>VQ_RXLEV

consideringAV_RXQUAL_UL_VQ: average on VQ_AVERAGE measurements of RXQUAL_ULAV_RXLEV_UL_VQ: average on VQ_AVERAGE measurements of RXLEV_ULNUM_UL_SAMPLES: total number of averages calculated on UL measurements during the call on the considered TRX

RMS11 = VQ_NOISY_DL_INTERFERENCE is incremented whenever a call verifies: 100*(INTERFERED_DL_SAMPLES / NUM_DL_SAMPLES) > VQ_INTF_THRESHOLD

with INTERFERED_DL_SAMPLES = nb of times when AV_RXQUAL_DL_VQ > VQ_RXQUAL and AV_RXLEV_DL_VQ>VQ_RXLEV

consideringAV_RXQUAL_DL_VQ: average on VQ_AVERAGE measurements of RXQUAL_DLAV_RXLEV_DL_VQ: average on VQ_AVERAGE measurements of RXLEV_DLNUM_DL_SAMPLES: total number of averages calculated on DL measurements during the call on the considered TRX

RMS12 = VQ_NOISY_UL_COVERAGE is incremented whenever a call verifies: 100*(BAD_COVERAGE_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLD

with BAD_COVERAGE_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL and AV_RXLEV_UL_VQ<=VQ_RXLEV

RMS13 = VQ_NOISY_DL_COVERAGE is incremented whenever a call verifies: 100*(BAD_COVERAGE_DL_SAMPLES / NUM_DL_SAMPLES) > VQ_INTF_THRESHOLD

with BAD_COVERAGE_DL_SAMPLES = nb of times when AV_RXQUAL_DL_VQ > VQ_RXQUAL and AV_RXLEV_DL_VQ<=VQ_RXLEV


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VQ_NOISY_UL_UNDEFINEDVQ_NOISY_UL_UNDEFINEDRMS14 = Number of calls suffering from both problems of interference and bad coverage on the uplink path

These calls are not counted in VQ_NOISY_UL_COVERAGE or VQ_NOISY_UL_INTERFERENCE

VQ_NOISY_DL_UNDEFINEDVQ_NOISY_DL_UNDEFINEDRMS15 = Number of calls suffering from both problems of interference and bad coverage on the downlink path

These calls are not counted in VQ_NOISY_DL_COVERAGE or VQ_NOISY_DL_INTERFERENCE


RMS14 = VQ_NOISY_UL_UNDEFINED is incremented whenever a call verifies: 100*(BAD_COVERAGE_UL_SAMPLES / NUM_UL_SAMPLES) <= VQ_INTF_THRESHOLDand 100*(INTERFERED_UL_SAMPLES / NUM_UL_SAMPLES) <= VQ_INTF_THRESHOLDand 100*(BAD_QUALITY_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLD

with BAD_COVERAGE_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL and AV_RXLEV_UL_VQ<=VQ_RXLEVINTERFERED_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUALand AV_RXLEV_UL_VQ > VQ_RXLEVBAD_QUALITY_UL_SAMPLES = INTERFERED_UL_SAMPLES + BAD_COVERAGE_UL_SAMPLES= nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL

RMS15 = VQ_NOISY_DL_UNDEFINED is incremented whenever a call verifies: 100*(BAD_COVERAGE_DL_SAMPLES / NUM_DL_SAMPLES) <= VQ_INTF_THRESHOLDand 100*(INTERFERED_DL_SAMPLES / NUM_DL_SAMPLES) <= VQ_INTF_THRESHOLDand 100*(BAD_QUALITY_DL_SAMPLES / NUM_DL_SAMPLES) > VQ_INTF_THRESHOLD

withBAD_COVERAGE_DL_SAMPLES = nb of times when AV_RXQUAL_DL_VQ > VQ_RXQUAL and AV_RXLEV_DL_VQ<=VQ_RXLEVINTERFERED_DL_SAMPLES = nb of times when AV_RXQUAL_DL_VQ > VQ_RXQUAL and AV_RXLEV_DL_VQ > VQ_RXLEVBAD_QUALITY_DL_SAMPLES = INTERFERED_DL_SAMPLES + BAD_COVERAGE_DL_SAMPLES= nb of times when AV_RXQUAL_DL_VQ > VQ_RXQUAL


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VQ_NOISY_UL_BAD_FERVQ_NOISY_UL_BAD_FERRMS16 = Number of calls with bad quality measurements and with bad FER measurements on the uplink path

Bad quality means bad RXQUAL whatever RXLEV is

VQ_NOISY_UL_GOOD_FERVQ_NOISY_UL_GOOD_FERRMS17 = Number of calls with bad quality measurements but with good FER measurements on the uplink path

VQ_ABNORMAL_BAD_FERVQ_ABNORMAL_BAD_FERRMS18 = Number of calls with fair quality measurements but with bad FER measurements on the uplink path


RMS16 = VQ_NOISY_UL_BAD_FER is incremented whenever a call verifies: 100*(BAD_QUALITY_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLDand 100*(BAD_QUAL_BAD_FER_UL_SAMPLES / BAD_QUALITY_UL_SAMPLES) > VQ_FER_THRESHOLD

withBAD_QUALITY_UL_SAMPLES = INTERFERED_UL_SAMPLES + BAD_COVERAGE_UL_SAMPLES= nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUALBAD_QUAL_BAD_FER_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL_VS_RXFER and AV_RXFER_UL_VQ > VQ_BAD_RXFER

consideringAV_RXFER_UL_VQ: average on VQ_AVERAGE measurements of FER

RMS17 = VQ_NOISY_UL_GOOD_FER is incremented whenever a call verifies: 100*(BAD_QUALITY_UL_SAMPLES / NUM_UL_SAMPLES) > VQ_INTF_THRESHOLDand 100*(BAD_QUAL_GOOD_FER_UL_SAMPLES / BAD_QUALITY_UL_SAMPLES) > VQ_FER_THRESHOLD

with BAD_QUALITY_UL_SAMPLES = INTERFERED_UL_SAMPLES + BAD_COVERAGE_UL_SAMPLES= nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUALBAD_QUAL_GOOD_FER_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ > VQ_RXQUAL_VS_RXFER and AV_RXFER_UL_VQ <= VQ_GOOD_RXFER

RMS18 = VQ_ABNORMAL_BAD_FER is incremented whenever a call verifies: 100*(FAIR_QUAL_BAD_FER_UL_SAMPLES / FAIR_QUALITY_UL_SAMPLES) > VQ_FER_THRESHOLD

withFAIR_QUALITY_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ < VQ_RXQUAL_VS_RXFER FAIR_QUAL_BAD_FER_UL_SAMPLES = nb of times when AV_RXQUAL_UL_VQ<VQ_RXQUAL_VS_RXFER and AV_RXFER_UL_VQ>VQ_BAD_RXFER




6.5 Radio quality statistics per TRX





6.5.1 Generalities


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6.5.1 Generalities TRX hardware problem

Suspecting a TRX hardware problem Average Path Balance

These RMS indicators are provided on the RNO tool per TRX, per Cell: Vector of the Number of Measurement Results per Path Balance bandRMPBV = RMS_PathBalance_sampleAverage Path Balance valueRMPBAN = RMS_PathBalance_avg

A Templates modification is needed to have more details.


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6.5.1 Generalities Vector counter

The real number of Measurement Results in which Path balance is in PATH BALANCE band j is equal to:

S(PATH BALANCE band j) x Max / 254 TPR_PATH_BALANCE(j) x MAX_PATH_BALANCE / 254

RMS7a=TPR_PATH_BALANCETPR_PATH_BALANCE RMS7b=MAX_PATH_BALANCEMAX_PATH_BALANCE

The vector counter system is used to provide: Path balance repartitionRadio Link counter (Consecutive Frame Erasure) repartitionC/I repartition

AMR FR/HR/DL/UL usage repartitionTA repartition (improved) B8


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6.5.1 Generalities Cell coverage problem

Suspecting a cell coverage problem

Distribution of samples per RxQual value and RxLev band

Distribution of samples per RxLev band

A coverage problem is observed when a significant amount of the traffic of a cell is suffering from both low level and bad quality (RxQual).To confirm the distribution of samples per RXLEV band, should also be considered to know the proportion of calls which are experiencing a low signal level.If a lot of samples of low level and bad quality are observed for only a sub-part of the TRXs (can be one only) then a BTS hardware problem or a problem on the aerials should be suspected.If all the TRXs are experiencing a lot of samples of low level and bad quality then a coverage problem shall be suspected. These RMS indicators are provided on the RNO tool per TRX, per Cell:

Matrix of Number of Measurement Results per DL RxQual value and per DL RxLev bandRMQLDSAM = RMS_DL_RxQuality_RxLevel_sampleVector of Percentage of Samples per DL RxLev bandRMQLDLVDV = RMS_DL_RxLevel_distribVector of Percentage of Samples per DL RxQual bandRMQLDQUDV = RMS_DL_RxQuality_distrib


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6.5.1 Generalities Matrix counter

TPR_RXQUAL_UL_RXLEV_ULTPR_RXQUAL_UL_RXLEV_UL TMR_RXQUAL_UL_RXLEV_ULTMR_RXQUAL_UL_RXLEV_UL

This counter RMS3a=TPR_RXQUAL_UL_RXLEV_UL is a matrix represented on the left side

This counter RMS3b=TMR_RXQUAL_UL_RXLEV_UL is a vectorrepresented on the right side

The real number of Measurement Results in which UL RxQual is equal to i and UL RxLev is in RXLEV band j, is equal to :

S(RXQUAL i, RXLEV band j) x Max j / 254

TPR_RXQUAL_UL_RXLEV_UL(i,j) x TMR_RXQUAL_UL_RXLEV_UL(j) / 254





6.5.2 Radio quality parameters


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6.5.2 Radio quality parametersRMS parameters (1/3)

Radio quality statisticsparameters used to define intervals for RXLEV, Path Balance,

Radio Link Counter and Consecutive Frame Erasure statistics

MEAS_STAT_LEV1 to MEAS_STAT_LEV9: 9 thresholds on the received radio level value defining 10 RXLEV bands

-110 ≤ MEAS_STAT_LEV(i+1) ≤ MEAS_STAT_LEV(i) < -47 dBm

MEAS_STAT_PATH_BAL1 to MEAS_STAT_PATH_BAL9: 9 thresholds on the radio signal propagation loss difference between UL and DL defining 10 Path Balance bands

-110 < MEAS_STAT_PATH_BAL(i) ≤ MEAS_STAT_PATH_BAL(i+1) ≤ +110 dB

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpt5 = TAB_PAR_MEAS_LEV = Table of 9 parameters MEAS_STAT_LEViRMSpt4 = TAB_PAR_MEAS_PATH_BALANCE = Table of 9 parameters MEAS_STAT_PATH_BALi

The Path Balance is computed by the BTS from each Measurement Result message as the difference between: Path loss on the uplink: received level by the BTS - MS power levelPath loss on the downlink: received level by the MS - BS power level

where the BTS power level is computed as the BTS nominal power minus by the BTS power relative level.Therefore the Path balance is computed as follows:

Path Balance = (RXLEV_UL - MS_TXPWR) - (RXLEV_DL - [BTS_MAX_OUTPUT_POWER - abs(BS_TXPWR)])

where RXLEV_UL is the received signal levels measured by the BTS on the uplink path (in dBm).MS_TXPWR is the MS transmitted power converted by the BTS from the MS power level into dBm value according to the frequency band of the TRX.BS_TXPWR is the BTS transmitted power offset defined relatively to the maximum absolute output power of the BTS (negative value in dB).BTS_MAX_OUTPUT_POWER is the maximum power of the BTS after Combiner (in dBm).RXLEV_DL is the received signal levels measured by the MS on the downlink path (in dBm).

NOTE: Additional asymetric DL loss (external combiner) or UL gain (TMA) are not taken into account in the computation, so they must be considered when interpreting the RMS results.


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Radio quality statistics

TA_STAT: threshold on the timing advance value defining a priori the range of the cell (0 to 64 bits)

MEAS_STAT_S1 to MEAS_STAT_S9: 9 thresholds on the BTS Radio Link Counter S value defining 10 S bands

0 < MEAS_STAT_S(i) ≤ MEAS_STAT_S(i+1) ≤ 128 SACCH mfrS: counter managed by the BTS on a per call basisS = RADIOLINK_TIMEOUT_BS if good radio conditionsS decremented if bad radio conditionsThe BSS triggers a call drop when S = 0

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpt3 = TAB_PAR_MEAS_STAT_S = Table of 9 parameters MEAS_STAT_SiRMSpb = PAR_TA_STAT

Recall on the Uplink Radio Link Supervision procedure:

For each active dedicated radio channel in a cell, a counter “S” called Radio Link Counter is:

decremented by 1 by the BTS each time an SACCH measurement from the mobile cannot be decoded (SACCH_BFI=1).

incremented by 2 by the BTS each time a valid SACCH measurement is received from the mobile (SACCH_BFI=0).

Initial value of S = RADIOLINK_TIMEOUT_BS (cell parameter)

if S reaches N_BSTXPWR_M, a radio link recovery is triggered (BTS and MS power increased at their maximum).

if S reaches 0, a Radio Link Failure is triggered (channel drop).

Therefore the value of S gives a measure of the “quality” of the radio uplink.


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MEAS_STAT_BFI1 to MEAS_STAT_BFI9: 9 thresholds on the number of consecutive speech frames with BFI set to 1 defining 10 BFI bands

0 < MEAS_STAT_BFI(i) ≤ MEAS_STAT_BFI(i+1) ≤ 25 speech frame

The BTS decodes 24 speech frames (sf) from 1 uplink SACCH multi-frame:

and 1 SACCH frame (or block)

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

SACCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

SACCH mfrTDMA: 4,616ms

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

SACCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

SACCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

SACCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

TCH

Sf 1 Sf 2 Sf 3 Sf 4 Sf 5 Sf 6 Sf 7 Sf 8 Sf 9 Sf 10 Sf 11 Sf 12 Sf 13 Sf 14 Sf 15 Sf 16 Sf 17 Sf 18 Sf 19 Sf 20 Sf 21 Sf 22 Sf 23 Sf 24

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpt2 = TAB_PAR_MEAS_STAT_BFI = Table of 9 parameters MEAS_STAT_BFIi

Consecutive Frame Erasure (CFE):

MEAS_STAT_BFIi parameters define 9 intervals of cumulated numbers of consecutive speech frames which have a Bad Frame Indicator value set to 1 (it means that the speech frame is considered as erroneous by the BTS).As the TC will erase speech frames for which a Bad Frame Indicator flag (BFI) has been set to the value 1 by the BTS, a BFI is used in the RMS counters description whereas the CFE is used in the RMS indicators defined in the RNO tool.

Note: By default, a BFI relates to a speech frame. When considering SACCH measurement, SACCH_BFI should be used.





6.5.3 Radio quality counters


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6.5.3 Radio quality counters RMS counters (1/7)

Radio quality statistics TPR_RXQUAL_UL_RXLEV_ULTPR_RXQUAL_UL_RXLEV_UL: matrix of 8x10 elements UL(RXQUAL i, RXLEV band j), each element is made up of:

Samplesij: norm of number of measurement result samples in which UL RxQual is equal to i and UL RxLev is reported in RXLEV band jMS PWR levelij: average value of MS power (in dBm) from pwr levels reported in these samplesTiming Advanceij: average value of TAs reported in these samples

TMR_RXQUAL_UL_RXLEV_ULTMR_RXQUAL_UL_RXLEV_UL: vector of 10 elements ULRXQUAL(RXLEV band j), each element is made up of:

the maximum value of the 8 real numbers of samples in which UL RxQual is equal to i (i=0 to 7) and UL RxLev is reported in RXLEV band j

RMS3a=TPR_RXQUAL_UL_RXLEV_UL RMS3b=TMR_RXQUAL_UL_RXLEV_UL

The real number of Measurement Results in which UL RxQual is equal to i and UL RxLev is in RXLEV band j, is equal to: S(RXQUAL i, RXLEV band j) x Max j / 254 TPR_RXQUAL_UL_RXLEV_UL(i,j) x TMR_RXQUAL_UL_RXLEV_UL(j) / 254


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Radio quality statistics TPR_RXQUAL_DL_RXLEV_DLTPR_RXQUAL_DL_RXLEV_DL: matrix of 8x10 elements DL(RXQUAL i, RXLEV band j), each element is made up of:

Samplesij: norm of number of measurement result samples in which DL RxQual is equal to i and DL RxLev is reported in RXLEV band jBS PWR levelij: average value of BS power (in dBm) from pwr levels reported in these samplesTiming Advanceij: average value of TAs reported in these samples

TMR_RXQUAL_DL_RXLEV_DLTMR_RXQUAL_DL_RXLEV_DL: vector of 10 elements DLRXQUAL(RXLEV band j), each element is made up of:

the maximum value of the 8 real numbers of samples in which DL RxQual is equal to i (i=0 to 7) and DL RxLev is reported in RXLEV band j

RMS4a=TPR_RXQUAL_DL_RXLEV_DL RMS4b=TMR_RXQUAL_DL_RXLEV_DL

The real number of Measurement Results in which DL RxQual is equal to i and DL RxLev is in RXLEV band j, is equal to:S(RXQUAL i, RXLEV band j) x Max j / 254 TPR_RXQUAL_DL_RXLEV_DL(i,j) x TMR_RXQUAL_DL_RXLEV_DL(j) / 254


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TPR_PATH_BALANCETPR_PATH_BALANCE: vector of 10 elements UL/DL(PATH BALANCE band j), each element is made up of:

the norm of number of measurement result samples for which the computed Path Balance is in PATH BALANCE band j

MAX_PATH_BALANCEMAX_PATH_BALANCE: the maximum value of the 10 real numbers of samples for which the computed Path Balance is in PATH BALANCE band j (j=1 to 10)

RMS7a=TPR_PATH_BALANCE RMS7b=MAX_PATH_BALANCE

The real number of Measurement Results in which Path balance is in PATH BALANCE band j, is equal to: S(PATH BALANCE band j) x Max / 254 TPR_PATH_BALANCE(j) x MAX_PATH_BALANCE / 254


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TPR_RADIO_LINKTPR_RADIO_LINK: vector of 10 elements UL(S band j), each element is made up of:

the norm of number of measurement result samples for which the Uplink Radio Link Counter is in S band j

MAX_RADIO_LINKMAX_RADIO_LINK: the maximum value of the 10 real numbers of samples for which the Uplink Radio Link Counter is in S band j (j=1 to 10)

RMS6a=TPR_RADIO_LINK RMS6b=MAX_RADIO_LINK

The real number of Measurement Results in which Uplink Radio Link Counter is in S band j, is equal to: S(S band j) x Max / 254 TPR_RADIO_LINK(j) x MAX_RADIO_LINK / 254


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TPR_BFI_RXLEV_ULTPR_BFI_RXLEV_UL: matrix of 10x10 elements UL(BFI i, RXLEV band j), each element is made up of:

the norm of number of SACCH multi-frames in which the number of consecutive speech frames with BFIs set to 1 is in BFI band i and UL RxLev reported in the corresponding measurement results is in RXLEV band j

TMR_BFI_RXLEV_ULTMR_BFI_RXLEV_UL: vector of 10 elements ULBFI(RXLEV band j), each element is made up of:

the maximum value of the 10 real numbers of SACCH multi-frames in which the number of consecutive speech frames with BFIs set to 1 is in BFI band i (i=0 to 9) and UL RxLevreported in the corresponding measurement results is in RXLEV band j

RMS5a=TPR_BFI_RXLEV_UL RMS5b= TPM_BFI_RXLEV_UL

The real number of Measurement Results in which the number of consecutive speech frames with BFIs set to 1 is in BFI band i and UL RxLev is in RXLEV band j, is equal to: S(BFI i, RXLEV band j) x Max j / 254 TPR_BFI_RXLEV_UL(i,j) x TMR_BFI_RXLEV_UL(j) / 254


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The BTS increments the BFI (or CFE) counter as soon as consecutive speech frames cannot be decoded

isolated speech frames with BFIs set to 1 are not countedsequences of not decoded speech frames are cumulated

SACCH mfr

CFE0 0 0 0 0 0 0 0 1 2 3 3 3 3 4 4 4 5 6 6 6 6 6 7 7

BFI

Sf 1 Sf 2 Sf 3 Sf 4 Sf 5 Sf 6 Sf 7 Sf 8 Sf 9 Sf 10 Sf 11 Sf 12 Sf 13 Sf 14 Sf 15 Sf 16 Sf 17 Sf 18 Sf 19 Sf 20 Sf 21 Sf 22 Sf 23 Sf 24 SACCH f.

0 0 0 1 0 0 0 1 1 1 1 0 0 1 1 0 1 1 1 0 1 0 1 1 0

RxLev UL10 11 9 12 12 11 11 10 3 2 0 8 9 5 3 7 2 1 2 7 3 8 2 3 5

Av_RxLev_UL= - 110 + INT[(10+11+9+12+12+11+11+10+3+2+0+8+9+5+3+7+2+1+2+7+3+8+2+3+5)/25]= -104 dBm


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PERC_TA_GT_TA_STATPERC_TA_GT_TA_STAT: percentage of measurement results reported with a Timing Advance value > TA_STAT parameter

MAX_TAMAX_TA: maximum value of Timing Advance among all TA values reported in the measurement results used for RMS

Corresponding RMS counter numbers: RMS36 = PERC_TA_GT_TA_STATRMS37 = MAX_TA




6.6 C/I statistics




6.6 C/I statistics

6.6.1 C/I Generalities


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6.6.1 C/I Generalities Storage and computation methods

In order to provide an efficient storage, the "vector method" already seen for previous RMS statistics will be used for C/I counters

C/I expressed in logarithmic scale (dB)(C/I)dB = CdBm - IdBm = 10 log10(CmW) - 10 log10(ImW)

= 10 log10(C/I)mW




6.6 C/I statistics

6.6.2 C/I Parameters


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6.6.2 C/I parameters RMS parameters

C/I statistics parameters defining intervals for C/I statistics

MEAS_STAT_C_I1 to MEAS_STAT_C_I9: 9 thresholds on the Carrier/Interference ratio defining 10 C/I bands

-63 < MEAS_STAT_C_I(i) ≤ MEAS_STAT_C_I(i+1) ≤ +63 dB

EN_BALANCED_CI: boolean indicating if the C/I value reported by the BTS is balanced or not

NEIGB_CELL_ID: (BCCH,BSIC) of the neighboring cell for which the C/I statistics per neighboring cell are reported

Frequency ARFCN: ARFCN of the frequency for which the C/I statistics per MAFA frequency are reported Annex 2

All these parameters are included in the RMS PM Type 31 result files as RMS counters: RMSpt1 = TAB_PAR_MEAS_STAT_C/I = Table of 9 parameters MEAS_STAT_C_IiRMSpa = PAR_EN_BALANCED_CIRMSp80 = NEIGB_CELL_IDRMSp90 = Frequency ARFCN

For C/I statistics per neighboring cell: The C/I ratio is computed by the BTS from each Measurement Result message as the difference between:

the downlink signal level measured by the MS on the serving TCH channel = C (dBm)the downlink signal level measured by the MS on the neighboring BCCH channel = I (dBm)

Two computation formulae may be used taking into account a corrective factor in case DL Power Control is used in the serving cell:

If EN_BALANCED_CI = Falsethen C/I (dB) = RXLEV_DL (dBm) - RXLEV_NCELL (dBm) else C/I (dB) = RXLEV_DL + abs(BS_TXPWR - BS_TXPWR_MAX) - RXLEV_NCELL

The expression (RXLEV_DL + abs(BS_TXPWR - BS_TXPWR_MAX)) can be seen as a kind of normalized received power level in case the BTS would always have used the maximum allowed transmit power level on the TCH channel.

For C/I statistics per MAFA frequency: The C/I ratio is computed by the BTS from each Extended Measurement Report message in the same way as the C/I ratio per neighboring cell.




6.6 C/I statistics

6.6.3 C/I Counters


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6.6.3 C/I counters RMS counters

C/I statistics per neighboring cell

TPR_CINTPR_CIN: vector of 10 elements C/In(C/I band j), each element is made up of:

the norm of number of measurement result samples for which the computed Carrier/Interference ratio is in C/I band j

MR_CINMR_CIN: maximum value of the 10 real numbers of samples for which the computed Carrier/Interference ratio is in C/I band j (j=1 to10)

TPR_CINTPR_CIN and MR_CINMR_CIN counters are provided for up to 42 neighboring cells

RMS8a=TPR_CIN RMS8b=TMR_CIN

For each reported neighboring cell (BCCH/BSIC): the Real number of Measurement Results for which the computed Carrier/Interference ratio is in C/I band j, is equal to: S(C/I band j) x Max / 254 TPR_CIN(j) x TMR_CIN / 254

For each declared/reported neighboring cell, the identification of this cell shall be done as follows:BCCH_ARFCN and BSIC. The BCCH ARFCN is deduced in the BTS from the BCCH frequency index and the list of indexed frequencies (sent by the BSC at the beginning of the RMS job). The RMS results report shall include all reported neighboring cells. Some of them correspond to known cells at the BSS level (i.e. their BSIC matches what is expected at the BSC side) but some of them are unknown (their BSIC does not match). However, the BTS will handle the same for both cases.The list of frequencies to be monitored by the mobile is limited to 33 but due to ‘resurgence’, the same frequency can be reported several times (each time with a different BSIC). If the number of reported cells is above the dimensioning limit (maximum 42 CI-vectors are reported), the extra new reported frequencies are not taken into account anymore. In the result report, the related overflow indicator is set accordingly.


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6.6.3 C/I counters RMS counters

C/I statistics per MAFA frequency

TPR_CIFTPR_CIF: vector of 10 elements C/If(C/I band j), each element is made up of:

the norm of number of Extended Measurement Results samples for which the computed Carrier/Interference ratio is in C/I band j

MR_CIFMR_CIF: maximum value of the 10 real numbers of samples for which the computed Carrier/Interference ratio is in C/I band j (j=1 to10)

TPR_CIFTPR_CIF and MR_CIFMR_CIF counters are provided for up to 21 frequencies (serving cell BCCH + 20 MAFA frequencies)

RMS9a=TPR_CIF RMS9b=TMR_CIF

For each reported MAFA frequency (ARFCN): the Real number of Extended Measurement Results for which the computed Carrier/Interference ratio is in C/I band j, is equal to: S(C/I band j) x Max / 254 TPR_CIF(j) x TMR_CIF / 254

For each reported MAFA frequency, the identification of this frequency shall be done as follows: Frequency ARFCN .

In case of a frequency reported via an Extended Measurement Reporting, no BSIC is required: the frequency ARFCN is not directly linked to a BCCH frequency. The ARFCN value of the frequency is deduced in the BTS from the place of the measurement in the EXTENDED_ MEASUREMENT_REPORT and from the ordered frequency list in the Extended Measurement Order. This list is built by the OMC-R and passed via BSC to BTS at the beginning of the RMS job.

The maximum number of frequencies in the order (EMO) is the maximum defined in GSM (=21). Hence the maximum in the report is 21 also. When in exceptional cases, more results are available (future expansion in GSM), only the first 21 are reported.

The BCCH frequency of the serving cell shall always be part of the EMO-frequency list.




6.7 RMS indicators usage


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6.7 RMS indicators usage Voice quality problem

Suspecting a Voice Quality problem RMS indicatorsPercentage of Noisy calls

FER is more reliable than RXQUAL to assess VQNoisy calls indicators can also be computed from FER measurements

Noisy calls with bad or good FERCalls not detected as noisy but with bad FER

Voice Quality indicators are based on calls

Noisy calls are associated with a cause of

bad coverage, interference or with an undefined cause

The fact that FER measurements are more reliable than RXQUAL ones to assess the VQ is even more true when using Slow Frequency Hopping. In this case, RXQUAL values are not anymore correlated to Voice Quality as perceived by the end user.FER measurements are available for the uplink path only.These RMS indicators are provided on the RNO tool per TRX, per Cell:

Number of Noisy calls suffering from problem of bad coverage on the uplink pathRMVQULVN = RMS_call_noisy_UL_bad_coverageNumber of Noisy calls suffering from problem of interference on the uplink pathRMVQUIFN = RMS_call_noisy_UL_interferenceNumber of Noisy calls suffering from problem of interference and bad coverage considered together on the uplink pathRMVQUUKN = RMS_call_noisy_UL_undefinedRate of Noisy calls suffering from problems of interference or/and bad coverage on the uplink pathRMVQUNOR = RMS_call_noisy_UL_rate

Note: The 4 indicators above can be provided for Noisy calls suffering of VQ problems on the dowlink path.Rate of Noisy calls but with good FER measurements on the uplink pathRMVQFEGR = RMS_call_noisy_good_FER_rateRate of Noisy calls and also with bad FER measurements on the uplink pathRMVQFEBR = RMS_call_noisy_bad_FER_rateRate of calls with fair quality measurements but with bad FER measurements on the uplink pathRMVQFEAR = RMS_call_abnormal_bad_FER_rate

This last indicator can be used in order to tune the RMS VQ parameters used to characterize a call as Noisy.


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6.7 RMS indicators usage Cell coverage problem

Suspecting a cell coverage problem

Distribution of samples per RxQual value and RxLev band

Distribution of samples per RxLev band

Not acceptablecoverage limit: Too low level Too bad quality

A coverage problem is observed when a significant amount of the traffic of a cell is suffering from both low level and bad quality (RxQual).To confirm the distribution of samples per RXLEV band, should be also considered to know the proportion of calls which are experiencing a low signal level.If a lot of samples of low level and bad quality are observed for only a sub-part of the TRXs (can be one only) then a BTS hardware problem or a problem on the aerials should be suspected.If all the TRXs are experiencing a lot of samples of low level and bad quality then a coverage problem shall be suspected. These RMS indicators are provided on the RNO tool per TRX, per Cell:

Matrix of Number of Measurement Results per DL RxQual value and per DL RxLev bandRMQLDSAM = RMS_DL_RxQuality_RxLevel_sampleVector of Percentage of Samples per DL RxLev bandRMQLDLVDV = RMS_DL_RxLevel_distribVector of Percentage of Samples per DL RxQual bandRMQLDQUDV = RMS_DL_RxQuality_distrib


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6.7 RMS indicators usage Cell coverage problem

Suspecting a cell coverage problem RMS indicatorsAverage TA values per RxQual value and RxLev band

Not acceptablecoverage limit: Too low level Too bad quality

Acceptable coverage limit: Sufficient level and good quality

% of TA value over TA threshold has also to be considered

In order to know if the coverage problem is due to a big amount of traffic at the cell border or rather to indoor calls, the average TA value per RXQUAL value and RXLEV band as well as the Percentage of TA values over the TA threshold should be observed.

Matrix of Average TA per UL RxQual value and per UL RxLev bandRMQLUTAM = RMS_UL_RxQuality_RxLevel_TimingAdvanceRate of Measurements Results whose TA is greater than the TA thresholdRMTAGTR = RMS_TimingAdvance_greater_threshold_rateMaximum TA value of all values reported in Measurement Results RMTAMXN = RMS_TimingAdvance_max


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6.7 RMS indicators usage RMS Exercise 1

Give the list of the RMS counters and parameters used in the 3 previous slides



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6.7 RMS indicators usage RMS exercise 2

What does this graph represent?Interpret this graph


These RMS indicators are provided on the RNO tool per TRX, per Cell: Vector of the Number of Measurement Results per Path Balance bandRMPBV = RMS_PathBalance_sampleAverage Path Balance valueRMPBAN = RMS_PathBalance_avg

A fair average Path Balance at Cell level can hide a bad value for one TRX.


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6.7 RMS indicators usage Cell interference problem

Suspecting a cell interference problemNumber of samples per RxQual value and RxLev band

Average DL RxQuality = 0.34

RMS results show no problemof radio link quality in this cell

Average RxQual value per RxLevband has also to be considered

These RMS indicators are provided on the RNO tool per TRX, per Cell: Matrix of Number of Measurement Results per DL RxQual value and per DL RxLev bandRMQLDSAM = RMS_DL_RxQuality_RxLevel_sampleVector of Average DL RxQual per RxLev bandRMQLDQUAV = RMS_DL_RxQuality_avg_per_RxLevelAverage DL RxQualityRMQLDQUAN = RMS_DL_RxQuality_avg


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Average RxQual value per RxLevband has also to be considered

Average DL RxQuality = 2.81


Interpret this graph


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Time allowed: 15 minutes Interpret this graph

These RMS indicators are provided on the RNO tool per TRX, per Cell: Matrix of the Number of Measurements Results per CFE band (or BFI band) and per UL RxLev band RMFEM = RMS_UL_ConsecutiveFrameErasure_RxLevel_sampleVector of the Average number of Consecutive Frame Erasure per UL RxLev bandRMFEBFAV = RMS_UL_ConsecutiveFrameErasure_avg_per_RxLevelVector of the Average UL RxQual per RxLev bandRMQLUQUAV = RMS_UL_RxQuality_avg_per_RxLevel


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Interpret this graph





6.8 Additional information


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6.8 Additional information RMS counters (1/3)

Counters used for: post-processing the RMS results provided per TRX

TOT_SEIZ_TCH: number of TCH channels successfully seized by the MSTOT_MEAS: number of Measurement Results used for RMSTOT_MEAS_L1INFO_NOL3INFO: number of Measurement Results used for RMS statistics for which Layer 1 info is present but Layer 3 is missingTOT_MEAS_DTX_UL: number of Measurement Results used for RMS statistics for which DTX UL was used in the corresponding SACCH mfrTOT_MEAS_DTX_DL: number of Measurement Results used for RMS statistics for which DTX DL was used in the corresponding SACCH mfrTOT_EMR: number of Extended Measurement Results used for RMS statistics

Corresponding RMS counter numbers: RMS31 = TOT_SEIZ_TCHRMS32 = TOT_MEASRMS33 = TOT_MEAS_L1INFO_NOL3INFORMS34 = TOT_MEAS_DTX_ULRMS35 = TOT_MEAS_DTX_DLRMS38 = TOT_EMR

Note: If during an SACCH measurement, DTX is applied on the uplink path (DTX_UL =1), the counters on consecutive BFIs(RMS5a, RMS5b) shall not be incremented and the corresponding measurement result shall not be taken into account in these RMS counters.If during an SACCH measurement, DTX is applied on the uplink path (DTX_UL = 1), the FER measurement does not take place.


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Counters used for: interpreting the RMS results provided per TRX

TRE_BAND: frequency band of the TRX BS_TX_PWRMAX: effective maximum output power of the BTS on any channel of the TRX as an offset from the maximum absolute outputpower (in dB)MS_TX_PWRMAX: effective maximum output power of the MS using any channel of the TRX (in dBm)IND_TRE_OVERLOAD: boolean indicating if the TRE handling the TRX function has experienced a data loss due to a processor overload during the RMS campaignIND_RMS_RESTARTED: boolean indicating if the RMS job has been restarted on the concerned TRE during the RMS campaign due to a modification of the RMS parameter values or a TRE reset

Corresponding RMS counter numbers: RMS20 = TRE_BANDRMSpw1 = BS_TX_PWRMAXRMSpw2 = MS_TX_PWRMAXRMS21 = IND_TRE_OVERLOADRMS22 = IND_RMS_RESTARTED


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Counters used for: interpreting the C/I RMS results provided per TRX

IND_CI_PARTIAL_OBSERVATION: made up of 2 booleans indicating that:

C/In computation has been restarted due to the modification of the list of neighboring cells during the RMS campaign

C/If computation has been restarted due to the modification of the list of MAFA frequencies during the RMS campaign

IND_CI_OVERFLOW: boolean indicating that the upper limit of 42 C/I sets of counters has been exceeded (each new reported neighboring cell (BCCH, BSIC) has not been taken into account in RMS statistics)

Corresponding RMS counter numbers: RMS23 = IND_CI_PARTIAL_OBSERVATIONRMS24 = IND_CI_OVERFLOW



7 TRAFFIC INDICATORS


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7 Traffic indicatorsSession presentation

Objective: to be able to describe BSS traffic indicators used for radio resource dimensioning

Program: 7.1 Call mix definition7.2 Basis of traffic theory7.3 TCH resource allocation indicators7.4 Resource occupancy indicators7.5 Traffic model indicators7.6 Preemption indicators




7.1 Call mix definition


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7.1 Call mix definitionGSM transactions

In a GSM Network, there are a lot of different transactions : location update: periodic, new updating, ~imsi_attach, ~imsi_detachHand Over (intra-cell, internal, external, etc.)SMS (Short Message Service, originating or terminating)SS (Supplementary Service)Pagingand also Originating and Terminating calls, etc.and so on (data, SMS-CB, etc.)

In a GSM network, telecom procedures involve different kinds of resource in the BSS: Location Update: RACH, AGCH, SDCCH and SCCPOriginated Call: RACH, AGCH, SDCCH, TCH and SCCPTerminated Call: PCH, RACH, AGCH, SDCCH, TCH and SCCPHandover: TCH, SCCP

etc.


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7.1 Call mix definitionGSM transactions

One can quantify the number of each transaction per hour

For example, for one cell, one can measure: 900 calls (600 TCs, 300 OCs)3600 LUs (any type)1350 HOs (900 internal, 450 external)100 SMSs5 SSs6000 pagings

With the following characteristicsmean call duration on TCH: 50 secondsmean SDCCH duration: 3.2 seconds

A Call mix can be defined through: data given by the Marketing team.data measured from the living network.

Before network design, a Call Mix is assessed from Marketing Studies or observations from other networks.After commercial opening, a Call Mix is measured from the real traffic.

Caution: Call duration means here TCH duration. The duration of a call from call setup to call release is an NSS notion.


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7.1 Call mix definitionExample

Set of such measurements is called "call mix"sometimes improperly called "traffic model"

Usually presented in the following way: Calls /hour : 900 (2/3 TC)LU/call : 4HO/Call : 1.5 (2/3 internal, 1/3 external)SMS/Call : 11 %SS/call : 5 %Paging/hour : 6000mean call duration on TCH : 90 secondsmean SDCCH duration : 4.2 seconds

After commercial opening, the number of calls per hour will be measured from traffic counters.Usually the Marketing team will provide:

on a per geographical area or morphostructure basis: the traffic per km2 (in Erlang),the traffic per subscriber (in mErl).

the number of calls per hour.


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7.1 Call mix definitionVariation

A call mix is varying a lot: from a cell to another

TCH traffic (induced by subscribers)number of LU/call and HO/call (induced by network design)

from one hour to anotherby default: busy hour

from one year to anothermodification of traffic intensity and distribution

On some university campus, an SMS/call is often higher than the average.


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7.1 Call mix definitionUsage

Interests of call mix: Input data for dimensioningCell and BSC resources dimensioning

RTCH, SDCCH, TTCH, BTS, BSC and MSC CPU processor

Some examples of "risky" call mix too many LU/Calls: SDCCH congestion, TCU load, MSC overloadtoo many HO/calls: speech quality, call drop, DTC loadtoo many calls: TCH congestiontoo many pagings: DTC processor load, PCH congestion

A Call Mix will be used at Radio Network Design and Radio Network Planning stages in order to define the capacity of the network(number of sites, TRXs per site, radio configuration, number of Abis-PCM, A-PCM).When the network is in operation, a Call Mix is used in order to anticipate network extension or re-dimensioning.


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7.1 Call mix definitionAdvises

Some advises

LU/CALL: 1 is "good", 2 is "bad", 4 and more can be dangerous

beware of the Network or BSC averages which can hide critical cells

HO/Call: less critical (1 is good)2 or 3 is not a direct problem, but the trend has to be monitored

Call: to be checked with an Erlang table (seen in next session)


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7.1 Call mix definitionExercise

Training exercise

Compute the call mix of a cell according the following information256 call/hour1300 LU/hour450 HO/hour

Is it complete? What are the risks of such a call mix?




7.2 Basis of traffic theory


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7.2 Basis of traffic theory Erlang definition

ERLANG: unit used to quantify traffic (intensity)T = (resource usage duration) / (total observation duration) [ERLANG]Example:

For 1 TCH, observed during 1 hourone can observe 2 calls: 1 of 80 seconds and 1 of 100 seconds

T = (80+100)/3600 = 0.05 ERLANG


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7.2 Basis of traffic theory Erlang from call mix

CALL MIX => ERLANGCall mix example:

350 call/hour3 LU/callTCH mean call duration: 85 secondsSDCCH mean duration: 4.5 seconds

Computation of Carried Erlang TCH = (350*85)/3600: 8.26 ERLANGSSDCCH = [ (350+350*3) * 4.5 ] / 3600 = 1.75 Erlang


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7.2 Basis of traffic theory Erlang B law

In a Telecom system, the call arrival frequency is ruled by the POISSON lawErlang B law: relationship between:

offered trafficnumber of resourcesblocking rate

call/second

0

1

2

3

4

5

6

7

8

9

10

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97

call/second

0

1

2

3

4

5

6

7

8

9

10

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97


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The call request arrival rate (and leaving) is not stablenumber of resources = average number of requests * mean durationis sometimes not sufficient => probability of blocking

=> Erlang B law Pblock: blocking probabilityN: number of resourcesE: offered traffic [Erlang]

Good approximation when the blocking rateis low (< 5 %)

7.2 Basis of traffic theory Erlang B law

Telecom system

Offered Carried

Rejected

P b lo ck N

k

N

k

k

N

EE

=

=∑!

!0

The Erlang B law is not fully accurate since it assumes that: the subscriber requests are not queued which is not always the case (TCH queued in the BSC),the subscriber does not repeat his call request if rejected, which is almost never the case.

Therefore the higher the blocking rate the worse is the approximation of the Erlang B law.

The Erlang C law modelizes better the TCH resource usage of the BSS since it takes into account the queuing. However the Erlang C law is never used since parameters like size of the queue and time spent into the queue have to be tuned.


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7.2 Basis of traffic theory Erlang B formulae

There are two different ways to use this law

Using Abacus

Using SW (here Excel)Pblock = f (T, Nc)Offered = f (Nc, Pblock)Channels = f (T, Pblock)


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7.2 Basis of traffic theory Erlang B abacus


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Example: 1 cell with 8 TRXs, with 60 TCH channels

Maximum blocking rate: 2 %

Erlang law: 50 Offered Erlang

83 % of TCH resources used to reach 2% of blocking

7.2 Basis of traffic theory Erlang B example


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But be careful, the Erlang B law is not linear:

In B4, we use for example a combined BCCH with a micro BTS.

4 SDCCHs, Pblock = 2% => T = 1.1 E25% resources used to reach 2% blocking

In B5, if we decide to provide SMSCB (Cell Broadcast information), 1 SDCCH stolen for CBCH

3 SDCCH, Pblock = 2% => T = 0.6 E25 % resources less => 50 % Traffic less!!

7.2 Basis of traffic theory Non linearity of Erlang B


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Given an Offered traffic, compute the number of TRXs (and SDCCH) needed to carry it => What is the accepted blocking rate?

default blocking rateRTCH: 2 %SDCCH: 0.5 %(for BSC TTCH: 0.1%)

7.2 Basis of traffic theory Cell dimensioning

The Erlang B law is less relevant for SDCCH dimensioning since SDCCH traffic cannot be modelized like TCH traffic. Indeed SDCCH is not only due to subscriber traffic but also to Location Update, SMS, IMSI Detach, etc.For SDCCH dimensioning, some typical configurations are used according to the number of TRXs in the cell, the LA plan.


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Cell dimensioning from call mix (bid, architecture)

to handle an offered traffic of 12 Erlangs (RTCH), compute the number of channels, then the number of TRXs

Channels (12;2%) = 19

example: 3 TRXs, 21 TCHs, 1 BCCH, 2 SDCCHs/8

7.2 Basis of traffic theory Dimensioning "a priori"


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Cell dimensioning from measurement (re-planning)

one is measuring a traffic of 15 Erlangs, with a blocking rate of 10 %how to dimension the cell?

Offered traffic = 15 / (1-10%) = 16.7 Erlangs!!!!Channels (16.7;2%) -> 25 TCHs -> 4 TRXs needed

7.2 Basis of traffic theory Dimensioning "a posteriori"


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Forecast traffic

traffic forecasting must be computed according to the offered traffic

not directly on the measured trafficIn order to plan the necessary actions soon enough, one must compute regularly the date when the traffic of a cell will become critical

Critical trafficcritical traffic: when the offered traffic will induce 2% of blocking traffic capacity of a cell = critical traffic of this cell

7.2 Basis of traffic theory Forecast / Critical traffic


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7.2 Basis of traffic theory Exercise

Training exercise: complete the form to get less than 2% of blocking

cell call mix info Erlang TCHOffered traffic

traffic forecast proposed config

12, 743 450 call/hourmean TCH call duration : 80secblocking rate TCH : 0.8%

10,08 Erlang TCH 30 % offered trafficincrease

13,1 Erlang TCH - > 20 TCH3 TRX

12,675 330 call/hourmean TCH call duration 129secblocking rate 4%

30 % offered trafficincrease

12,865 600 call/hourmean TCH call duration 96secblocking rate 8 %

30 % offered trafficincrease




7.3 TCH resource allocation indicators


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7.3 TCH resource allocation indicators Radio Allocation and Management

Radio resource allocation and management aim at:

managing pools of TCH resources by: evaluating the load and traffic situation of one celladapting the handling of resources according to these evaluations

Allocating dedicated radio resources by: determining the type of resource to be provided for a request and checking the availability of such resourceselecting the best resource according to several criteria


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7.3 TCH resource allocation indicators TCH allocation process

TCH request

TCH rejected TCH queued

TCH allocation

TCH selection

channel type (FR,HR,DR)speech version (FR, HR, EFR, AMR FR, AMR HR)request type (NA or HO)

cell channel type capabilitycell codec type capability

cell load

TCH free?

Queuing?

no yes

no yesTCH pool (FR,DR,HR) selecting criteria

Inputs for TCH allocation function: requirements from the MSC:

channel type (mandatory) is one of the following:

list of preferred speech version (optional): GSM full rate speech version 1 = FRGSM full rate speech version 2 = EFRGSM full rate speech version 3 = AMR FRGSM half rate speech version 1 = HRGSM half rate speech version 3 = AMR HR

capabilities of the cell: FR TCHs only if only FR TRXs / FR+HR TCHs if some DR TRXscodec supported among: FR, EFR, AMR FR, HR, AMR HR

FR Full Rate onlyHR Half Rate onlyDR FR P NCA Dual Rate Full Rate Preferred No Changes Allowed after first channel allocation

as a result of the requestDR FR P CA Dual Rate Full Rate Preferred Changes Allowed after first channel allocation as a

result of the requestDR HR P NCA Dual Rate Half Rate Preferred No Changes Allowed after first channel allocation

as a result of the requestDR HR P CA Dual Rate Half Rate Preferred Changes Allowed after first channel allocation as a

result of the requestDR SV P NCA Dual Rate No Changes of channel rate Allowed after first channel allocation as a

result of the requestDR SV P CA Dual Rate Changes of channel rate Allowed after first channel allocation as a

result of the request


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7.3 TCH resource allocation indicators TCH pools

3 pools of TCH resources are managed per cell: Full Rate TCH pool containing the free resources of FR TRXs

Dual Rate TCH pool containing the free resources of DR TRXs

Half Rate TCH pool containing the free HR resources of DR TRXs whose mate HR TCH is busy

FR channels can be allocated on both FR and DR TRXs whereas HR can only be allocated on DR TRXs


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7.3 TCH resource allocation indicators Cell load influence

TCH allocation with list of preferred speech versionscell load = False

preferred SV list kept as given by the MSCcell load = True

preferred SV list reordered: HR SV 1st, FR SV 2nd

TCH allocation without list of preferred speech versionsif DR HR Preferred request

try to allocate HR TCHif DR FR Preferred request

try to allocate HR TCH if cell load = Truetry to allocate FR TCH if cell load = False


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7.3 TCH resource allocation indicators HR allocation and release

Example of pool management: HR allocation and release

HR pool preferred DR pool selected if HR pool empty

DR HR

Request for a TCH HR Release of a TCH HR

BTS dual rateBTS dual rate

+1 TCH HR (2)

-1 TCH DR

(1)(2)

(2)

(1) : Pool HR not empty(2) : Pool HR empty

DR HR

-1TCH HR (1)

+ 1TCH DR

(2)(1)

(1)

(1) : Associated HR free(2) : Associated HR busy

+1TCH HR (2)

- 1 TCH HR (1)

FR FR


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7.3 TCH resource allocation indicators FR / HR allocation

FR / HR allocation discrimination for DR HR requestcell load AV_LOAD() computed from

load samples = (NB_BUSY_TS / NB_TS) * 100non-sliding window (LOAD_EV_PERIOD) averaging process

∑ −1- RIODLOAD_EV_PE

0 =i

i)e(kLoad_sampl RIODLOAD_EV_PE

1 = AV_LOAD(k)

100%

AV_LOAD()

THR_FR_LOAD_U_SV1= 80%

THR_FR_LOAD_U_SV3=60%

timeTHR_FR_LOAD_L_SV1=50%

THR_FR_LOAD_L_SV3=40%

Load samples are computed by the BSC every TCH_INFO_PERIOD = 5 seconds.LOAD_EV_PERIOD is the averaging window size for cell load computation. It is equal to 12 but it can be changed at the OMC-R level on a per cel basis.Therefore the cell load process has a periodicity of 1mn by default (TCH_INFO_PERIOD*LOAD_EV_PERIOD).The allocation of Half rate resources is decided upon the load evaluation in the serving cell.AMR HR (HR SV3) offers a better speech quality than HR SV1. The Alcatel BSS offers thus the possibility to define a set of thresholds specific for AMR. If the load increases, AMR HR capable MSs can be the first to be allocated in HR (HR SV3) for load reasons, and if the load still increases, then all the MSs HR capable can be allocated in HR (HR SV1 & HR SV3) for load reasons.That is why two variables of load are defined: LOAD_SV3 and LOAD_SV1.Each load variable is calculated through its own threshold set: the thresholds related to the variable LOAD_SV3 (THR_FR_LOAD_U_SV3 and THR_FR_LOAD_L_SV3). They are less restrictive than the ones related to the variable LOAD_SV1 (THR_FR_LOAD_U_SV1 and THR_FR_LOAD_L_SV1).As a consequence, if the load of the cell increases, then the variable LOAD_SV3 will first equal TRUE, and if the load still increases, the variable LOAD_SV1 will then equal TRUE.The variable LOAD_SV1 corresponds to a level of load where it is important to put as many MSs on half rate TCH as possible: HR SV3 or HR SV1.

The same computation is done to compute LOAD_SV3 with the thresholds: THR_FR_LOAD_U_SV3 and THR_FR_LOAD_L_SV3 with the following relations:

THR_FR_LOAD_L_SV3 ≤ THR_FR_LOAD_U_SV3THR_FR_LOAD_U_SV3 ≤ THR_FR_LOAD_U_SV1THR_FR_LOAD_L_SV3 ≤ THR_FR_LOAD_L_SV1

Previous stateAV_LOAD

LOAD_SV1 = FALSE LOAD_SV1 = TRUE

AV_LOAD ≤ THR_FR_LOAD_L_SV1 LOAD_SV1 = FALSE LOAD_SV1 = FALSETHR_FR_LOAD_L_SV1 <

AV_LOAD ≤THR_FR_LOAD_U_SV1

LOAD_SV1 = FALSE LOAD_SV1 = TRUE

THR_FR_LOAD_U_SV1 < AV_LOAD LOAD_SV1 = TRUE LOAD_SV1 = TRUE


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7.3 TCH resource allocation indicators TCH pool selection

TCH allocation without list of preferred speech versionsFR request: FR pool DR poolHR request: HR pool DR poolDR FR Preferred request:

cell load=False: FR pool DR pool HR pool cell load=True: HR pool DR pool FR pool

DR HR Pref. request: HR pool DR pool FR pool

TCH allocation with a list of preferred speech versionsFR SV: FR pool DR poolHR SV: HR pool DR pool


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7.3 TCH resource allocation indicators TCH selection

The TCH is chosen from the selected pool according to the following criteria:

The Best quality of service for TCH calls is performed by selecting the TCH resources according to the following ordered criteria: 1. Exclusion of TS reserved for GPRS

In the PDCH groups defined by the BSC to support GPRS traffic, the TS consecutive to the already allocated PDCHs (or the TS on the left side of the PDCH group if no PDCH is allocated) shall be put in the lowest selection priority so that GRPS connections can be more easily established.

2. TS with the highest Trx Preference Mark

According to the frequency plan, the coverage and interference probability of a cell (or according to measurements), the operator may know which TRX should be a priori favored for TCH selection. For that purpose, it is possible for operators to give a preference mark to each TRX of a cell. This mark is given through the parameters TRX_PREF_MARK (TPM) changeable at OMC-R side per TRX. The range of TRX_PREF_MARK will be from 0 (lowest priority) to 7 (highest priority). The TCH selection function favours the channels with the highest TPM.

3. TS with the biggest Mobile Allocation

Considering that the number of frequencies is a key factor for the average quality of channels, the TCH selection function favors the TS with the biggest MA (i.e. with the most frequencies in their frequency hopping sequence). This selection criterion is enabled/disabled via the flag EN_MA_SELECTION changeable at the OMC-R side on a per cell basis.

4. TS from the best Interference Band

Considering that the uplink received level measured by the BTS on an idle channel is a means to assess the quality when in connected mode, the TCH selection function favors the TS belonging to the best Interference Band (IB). Five IBs are defined through 5 parameters INTFBD1 to INTFBD5 where INTFBD(i)< INTFBD(i+1) and INTFBD5 = -47 all changeable at the OMC-R side on a per BTS basis.

5. TS with the highest TS index on the TRX with the highest TRX idThis last criterion allows to separate the TCH and PDCH allocations so as to avoid CS and PS conflicts on a given TRX. Furthermore, it aims at optimizing radio resource allocations to provide the best throughput for GPRS traffic.

If more than one TRX is considered, select the TRX with the highest TRX-id.If more than one timeslot is candidate, select the candidate TS having the highest timeslot index (at the right side of the TRX).


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7.3 TCH resource allocation indicators MS access

MS access types distribution (NA only)B8: Accessibility in type 110

TCH requests from FR only MSTCNARQMN= MC701A

TCH requests from DR MSTCNARQBN= MC701B

TCH requests from DR+EFR MSTCNARQTN= MC701C

TCH requests from AMR MSTCNA3RQTN= MC701D

TCH requests from Data callsTCNARQDN= MC701E

B8 (See comments)

Modified in B8

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > TCH traffic > Speech version and Channel type

These indicators can only be computed if PM Type 1 is activated in B7.In B8, the counters needed for these indicators are added to type 110.

The following indicators are also computed: Ratio of TCH normal assignment requests from FR mobiles over all TCH normal assignment requests from all mobile types = TCNARQMTO = MC701A / (MC701A+MC701B+MC701C+MC701D+MC701E)Ratio of TCH normal assignment requests from DR mobiles over all TCH normal assignment requests from all mobile types = TCNARQBTO = MC701B / (MC701A+MC701B+MC701C+MC701D+MC701E)Ratio of TCH normal assignment requests from DR+EFR mobiles over all TCH normal assignment requests from all mobile types = TCNARQTTO = MC701C / (MC701A+MC701B+MC701C+MC701D+MC701E)Ratio of TCH normal assignment requests from AMR mobiles over all TCH normal assignment requests from all mobile types = TCNA3RQTTO = MC701D / (MC701A+MC701B+MC701C+MC701D+MC701E)Ratio of TCH normal assignment requests for Data calls over all TCH normal assignment requests from all mobile types = TCNARQDTO = MC701E / (MC701A+MC701B+MC701C+MC701D+MC701E)

Number of handover intracell attempts with cause 27: "FR to HR channel adaptation due to a good radio quality" on a TCH channel= HCSTAMFN = MC448BNumber of handover intracell attempts with cause 26: "HR to FR channel adaptation due to a bad radio quality" on a TCH channel= HCSTAMHN = MC448A


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7.3 TCH resource allocation indicators Speech coding version

Speech coding Version capabilities distribution (NA only)B8: Accessibility in type 110

TCH allocations with FR SV1TCNACAFN= MC702A

TCH allocations with HR SV1 TCNACAHN= MC702B

TCH allocations with FR SV2 (EFR) TCNACAEN= MC702C

TCH allocations with FR SV3 (AMR FR) TCNA3CAFN= MC704A

TCH allocations with HR SV3 (AMR HR) TCNA3CAHN= MC704B

TCH allocations for data call TCNACADN= MC705

B8 (See comments)

Modified in B8

These 2 counters are

new in B8.

In B7, only one

without details: MC704

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > TCH traffic > Speech version and Channel type

These indicators can only be computed if PM Type 1 is activated in B7.In B8, the counters needed for these Indicators are added to type 110.

The following indicators are also computed: Ratio of TCH allocations with FR SV1 over all TCH allocations during normal assignment = TCNACAFTO = MC702A / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)Ratio of TCH allocations with HR SV1 over all TCH allocations during normal assignment = TCNACAHTO = MC702B / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)Ratio of TCH allocations with EFR over all TCH allocations during normal assignment = TCNACAETO = MC702C / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)Ratio of TCH allocations with AMR FR over all TCH allocations during normal assignment = TCNA3CAFTO = MC704A / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)Ratio of TCH allocations with AMR HR over all TCH allocations during normal assignment = TCNA3CAHTO = MC704A / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)Ratio of TCH allocations for Data calls over all TCH allocations during normal assignment = TCNACADTO = MC705 / (MC702A+MC702B+MC702C+MC704A+MC704B+MC705)

Rate of successful TCH allocations with AMR SV over all AMR MS requests= TCNA3SUR = (MC704A+MC704B) / MC701D


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7.3 TCH resource allocation indicators Distributions

FR/HR calls distribution (NA+HO) FR TCH allocation ratioTCAHCAFO = MC370A / (MC370A+MC370B)

HR TCH allocation ratioTCAHCAHO = MC370B / (MC370A+MC370B)

NA/HO distribution Normal Assignment TCH allocation ratioTCNACAO = MC703 / (MC703 + [MC15A+MC15B])

Handover TCH allocation ratio TCHOCAO = [MC15A+MC15B] / (MC703 + [MC15A+MC15B])

TCH allocation distribution per TRXNumber of TCH allocations for Normal AssignmentTCNACAN = MC703

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > TCH traffic > Resource occupancy

MC370A = Number of FR TCH allocations (FR+EFR+AMR FR)MC370B = Number of HR TCH allocations (HR+AMR HR)

MC703 = Number of TCH allocations for Normal Assignment.MC15A = Number of TCH allocations for Internal Directed Retry.MC15B = Number of TCH allocations for Handover (intra cell, internal, external).

TCNACAN indicator is also available as the MAX value of the day on the A9156 RNO tool.

Some of these indicators are also available for SDCCH: SDCCH allocation distribution per TRX through the number of SDCCH allocations

SDAHCAN = MC390SDCCH Assignment/HO distribution through the ratio of SDCCH allocations for Assignment

SDNACAO = MC148 / MC390




7.4 Resource occupancy indicators


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7.4 Resource occupancy indicatorsTCH resource

TCH resource occupancyTCH traffic in ErlangTCTRE= (MC380A+MC380B) / 3600

TCH mean holding time (TCH average duration)TCTRMHT= (MC380A+MC380B) / (MC370A+MC370B)

FR TCH traffic in ErlangTCTRE= MC380A / 3600

FR TCH mean holding timeTCTRFMHT= MC380A/ MC370A

HR TCH traffic in ErlangTCTRE= MC380B / 3600

HR TCH mean holding timeTCTRHMHT= MC380B/ MC370B

B8 (See comments)

New B8

A split of the counters 380a and b

provides information about multiband

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > TCH traffic > Resource occupancy

MC380A = Cumulated FR TCH duration per TRXMC380B = Cumulated HR TCH duration per TRX

The following indicators can also be computed: TCTRME = Multiband MS TCH traffic in Erlang = MC381 / 3600TCTRSE = Single band MS TCH traffic in Erlang = ([MC380A+MC380B] - MC381) / 3600

MC381 = Cumulated (FR+HR) TCH duration of Multiband mobiles per TRX

In B8, a split of counters (MC380a and MC380b) is added to make the distinction between traffic in different frequency bands: here after the corresponding stored indicators (type 110):

TCTRFTTGT = Time (in seconds) during which the TCH radio timeslot or dynamic SDCCH/8 timeslot in the GSM frequency band is busy in FR usage = MC380CTCTRHTTGT = Time (in seconds) during which the TCH radio timeslot or dynamic SDCCH/8 timeslot in the GSM frequency band is busy in HR usage = MC380DTCTRFTTDT = Time (in seconds) during which the TCH radio timeslot or dynamic SDCCH/8 timeslot in the DCS/PCS frequency band is busy in FR usage = MC380ETCTRHTTDT = Time (in seconds) during which the TCH radio timeslot or dynamic SDCCH/8 timeslot in the DCS/PCS frequency band is busy in HR usage = MC380F

B8


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7.4 Resource occupancy indicatorsSDCCH / ACH resource

SDCCH resource occupancySDCCH traffic in ErlangSDTRE= MC400 / 3600

SDCCH mean holding time (SDCCH average duration)SDTRMHT= MC400 / MC390

ACH resource occupancyACH traffic in ErlangC750 / 3600

ACH mean holding time (ACH average duration) QSTRN =C750 / C751

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > SDCCH traffic > Resource occupancy

MC400 = Cumulated SDCCH duration per TRXMC380 = Number of SDCCH allocations per TRX

C750 and C751 are 2 counters introduced from B7 in type 18. Both are provided per TTCH (A channel): C750 = TIME_A_CHANNEL_BUSY: Time (in seconds) during which the A channel is busy (allocated).C751 = NB_A_CHANNEL_ALLOC: Number of allocations of the A channel.




7.5 Traffic model indicators


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7.5 Traffic model indicatorsSDCCH establishment

SDCCH establishment cause distributionRatio of MT callsTMMTO= MC01 / SDCCH ASSIGN SUCCESS

Ratio of MO normal and emergency callsTMMTO= MC02H / SDCCH ASSIGN SUCCESS

Ratio of LU normal (resp. follow-on)TMMOLUR = MC02A (resp. MC02D) / SDCCH ASSIGN SUCCESS

Ratio of IMSI detachTMMOLUDR= MC02G / SDCCH ASSIGN SUCCESS

Ratio of Short Message ServiceTMMOSMSR= MC02B / SDCCH ASSIGN SUCCESS

Ratio of Supplementary ServiceTMMOSSR= MC02C / SDCCH ASSIGN SUCCESS

Ratio of Call re-establishmentTMMOCRR= MC02E / SDCCH ASSIGN SUCCESS

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > SDCCH traffic > Traffic model

SDCCH ASSIGN SUCCESS = Total number of SDCCH establishments for network access = MC01 + MC02

These indicators allow to get call mix data from the network.


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7.5 Traffic model indicatorsMobiles penetration

E-GSM mobiles penetrationRatio of E-GSM MS access over all MS accesses (except LU)TMMSEGR = MC706 / ([MC01+MC02]-[MC02A+MC02D+MC02G])

Multiband mobiles penetrationRatio of Multiband MS access over all MS accesses (except LU)TMMSMBR = MC850 / ([MC01+MC02]-[MC02A+MC02D+MC02G])

AMR mobiles penetrationRatio of TCH allocation for AMR MS over all TCH allocationsTCTR3CATTO = MC704A+ MC704B / MC703

TFO calls ratioRatio of successful TFO establishment over all TCH allocationsQSTRCCTR = MC170 / MC703

Handover per CallNumber of Handovers (intra cell,internal,external) per Normal AssignmentTMHOCO = (MC717A+MC717B) / MC718

B8

New B8

(See comments)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: Traffic Load and Traffic Model > SDCCH traffic > MS penetration rateTraffic Load and Traffic Model > TCH traffic > Speech version and Channel type

[MC01+MC02]-[MC02A+MC02D+MC02G] = Total number of initial accesses for call establishment (except location update) MC706 = Number of initial accesses for call establishment (except location update) of MS supporting the E-GSM bandMC850 = Number of initial accesses for call establishment (except location update) of MS supporting two frequency bands (ex: GSM900 and DCS1800)MC703 = Total number of TCH allocations (FR+HR) for Normal AssignmentMC704A = Number of TCH allocations (FR) for Normal Assignment of AMR mobiles onlyMC704B = Number of TCH allocations (HR) for Normal Assignment of AMR mobiles only

MC704 (Allocation AMR FR+HR) is removed in B8MC170 = Number of TCH calls for which a TFO has been successfully established

B8




7.6 Preemption indicators


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7.6 Preemption indicatorsPreemption principle

Preemption attributes (in Assignment or HO Request): pci : preemption capability indication

indicates if the call can preempt another call (pci=1) or not

pvi : preemption vulnerability indicationindicates if the call is preemptable (pvi=1) or not

priority level: 1=highest priority / 14=lowest priority

Preemption rules:A TCH request with pci=1 and priority level=p1 will preempt an on-going call with pvi=1 and priority level=p2, p2 lower than p1 (whatever pcivalue)the on-going call with the lowest priority level value shall be elected first and if several calls have the same lowest p2 value, one of them with pcibit set to 0 is preferred

On Preemption capable TCH Request occurrence: 1. The TCH is established through Preemption if a lower priority level on-going call is preemptable. In this case, the on-going

call is released and the freed TCH is served to the new request.2. If no preemption is possible:

If queuing is possible: the TCH request is queued and either a Directed Retry or a Fast Traffic HO can be performed.If queuing is not possible: the TCH request is rejected and an ASSIGNMENT or HANDOVER FAILURE "no radio resource available" message is sent to the MSC.


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7.6 Preemption indicatorsPreemption counters

MC921A = Number of TCH Requests with the capability to preempt another call with lower priority (pci=1) MC921B = Number of preemption capable TCH Requests (pci=1) served with TCH resource (with or without using the preemption feature).MC921C = Number of preempted callsMC921D = Number of preemption capable TCH Request (pci=1) successfully served in a neighboring cell with the help of the directed retry procedureMC921E = Number of preemptable calls successfully established (pvi=1)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS> RTCH > Preemption feature


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7.6 Preemption indicators

Preemption capable TCH Request rejection rateTCPPFLCR = (MC921A-MC921B-MC921D) / MC921A

Ratio of preemption capable TCH Request which led to a successful Directed Retry

TCPPDSUCR = MC921D / MC921A

Ratio of preemptable calls established over all callsTCPPSUVO = MC921E / (MC718+MC717A+MC717B)

Refer to BSS - DEFINITION OF QUALITY OF SERVICE INDICATORS RELEASE B8: GLOBAL Quality of service INDICATORS> RTCH > Preemption feature


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Thank you for answeringthe self-assessment

of the objectives sheet

Introduction to QoS and Traffic Load monitoring / B8Evaluation

Objective: to be able to interpret:

Global indicators, in order to assess the general quality of the networkDetailed indicators, in order to detect / identify / locate the main malfunctionsHandover indicators, in order to quantify the efficiency and the reason for HODirected retry indicators, in order to quantify the efficiency of a directed retryIndicators provided by the new RMS feature to ease radio optimization and fault detectionTraffic indicators, in order to detect/predict overload and compute adequate cell dimensioning as well as to understand how RTCH resources are used in the network


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Radio Measurement Reporting

ANNEX 1



1.323

Radio measurement mechanismsMS connected (TCH or SDCCH)The serving cell gives to the MS the list of the neighboringcells to listenEvery SACCH, the MS reports to the serving cell: measurement report message

Received level of 6 best cells (which can change)DL level and quality of serving cell


MeastReport


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Radio measurement mechanismsFor each MS connected to the BTS (TCH or SDCCH)


BSC

DL measurements UL+DL measurements

The UL received level and quality are measured every SACCH

The Timing advance (TA) is computed

The UL information is gathered into a measurement report

this is the message result sent by the BTS to the BSC

MeastReport

MeastResult


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Measurement Result message


L1 Info

L3 Info

MeasurementReportFrom the MS

Back

Basically, the MEASUREMENT RESULT message is composed of: L1 info: SACCH Layer 1 header containing MS_TXPWR_CONF and TOA.L3 info: MEASUREMENT REPORT from the MS. This message contains the downlink measurements and neighboringcell measurements.Uplink measurements performed by the BTS.BTS power level used.

SUB frames correspond to the use of DTXif the mobile is in DTX, the rxlevsub or rxqualsub is used to avoid measuring the ts where there is nothing to transmit in order not to false measurements.else rxlevfull is used that is to say all TSs are measured.

MS TXPOWER CONF: what is the actual power emitted by the MS.

TOA is the timing advance.

SACCH BFI: bad frame indicator; 2 values 0 or 1; 0 means that the BTS succeeded in decoding the measurement report from the MS.

How the neighboring cells are coded:BCCH1 index in BA list /BSIC1; BCCH2 index in BA list/BSIC2. Why? Because when the mobile is connecting to a new cell, it does not receive LAC/CI (too long) but the list of BCCH frequencies of the neighboring cells (in Band Allocation: BA list). When it reports the radio measurements, it gives the index of the BCCH frequency in the BA list instead of BCCH ARFCN due to the length in case of 1800 frequency coding. Besides the mobile may report a BCCH index / BSIC which does not correspond to a neighboring cell. Of course the BSC will not trigger any handover except if this BCCH index / BSIC couple correspond to a neighboring cell.


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Extended Measurement Reporting

ANNEX 2

Extended Measurement Reporting(MAFA)


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The Extended Measurement Reporting is a feature allowing the BSS to request an MS to measure and report up to 21 frequencies of the band that are not included in its BA list

Such phase 2+ mobiles must support the optional MAFA feature (Mobile Assisted Frequency Allocation)


1.328





< --------------------------------------------------------CHANNEL ACTIVATION (TCH)

(EMO included)-------------------------------------------------------- >CHANNEL ACTIVATION ACKNOWLEDGE

.

.TCH establishment.

--------TCH---------> .ASSIGNT COMPLETE ------------------------------------------------------- >

ASSIGNMENT COMPLETE ----------------------------------- ><------SACCH-------- ASSIGNMENT COMPLETE

--------SACCH------><------SACCH--------

--------SACCH------><-------SACCH--------

EMO(MAFA freq. List)

--------SACCH------>EMR

(MAFA freq. RxLev)<------SACCH--------

--------SACCH------>

Extended Measurement Reporting mechanisms


The Extended Measurement Order includes the MAFA frequencies the MS is asked to measureEMO sent once to the MS on SACCH after TCH seizureExtended Measurement Results include the average signal level measured on each MAFA frequency over one SACCH mf durationEMR received once per call on SACCH

Back

When the BTS receives a CHANNEL ACTIVATION with the Extended Measurement Order (EMO) included, it shall send this information on the SACCH to the corresponding mobile only once.When the BTS has to send this information, it shall replace the sending of system information 5, 5bis, 5ter or 6 by this information. At the next SACCH multi-frame, the BTS shall resume the sending of this system information by the replaced one. The EMO shall be sent after 2 complete sets of SYS_INFO5 and 6, i.e. after the 2nd SYSINFO 6 after the reception of SABM. This guarantees the MS has received a complete set.Then, the BTS normally receives from the MS an EXTENDED MEASUREMENT RESULT with the level of the frequencies to monitor. The BTS shall make the correlation between these levels and the frequencies contained in the latest EMO information, after having decoded them, according to the order of the ARFCN. The ‘EXTENDED_MEASUREMENT_RESULT’ is NOT forwarded to the BSC, instead a ‘MEASUREMENT_RESULT’ with indication ‘no_MS_results’ is sent to the BSC.In particular, the BTS shall identify the level of the BCCH frequency of the serving cell (which shall always be part of the frequencies to monitor) and apply it as the RXLEV_DL in the Radio Measurement Statistics. The other frequencies will be considered in the same way as BCCH frequency of neighboring cells: they will be linked to the neighboring level and C/I statistics.


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ANNEX 3

GSM BSS Protocol Stacks



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Signaling Links

A-Interface MT-Link signaling #7 System with SCCPMSC BSC

BSC BTSAbis Interface RSL with LAPD Protocol

BTS MSAir-Interface (CCCH/SACCH/FACCH) with LAPDm Protocol

BSC OMC-ROML Link with X25 connection LAPB Protocol



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The reference Model

7 Application

6 Presentation

4 Transport

5 Session

2 Data Link

3 Network

1 Physical

User of Transport Service

Transport ServiceNetworkService



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Layer 1Physical; Responsible for the transparent transmission of information across the physical medium (HDB3, PCM, AMI)

Layer 2Data Link; Responsible for providing a reliable transfer between the terminal and the network (#7, LAPD,etc.)

Layer 3Network; responsible for setting up and maintaining the connection across a network (CM, MM, RR, Message routing, etc.)



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Layer 4Transport; responsible for the control of quality of service (Layer of information)

Layer 5Session; Handles the coordination between the user processes (Set up transfer of information)

Layer 6Presentation; responsible for ensuring that the information is presented to the eventual user in a meaningful way (Type format. Ex. ASCII)

Layer 7Application; provides user interface to lower levels (Operating System)



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BTS PSTNISDN

Air Intfc Abis Intfc A Intfc B .. F Intfc

MS BSC MSC

CM

MM

RR

LAPDm

digit

radio

RR BSSAP

LAPDm LAPD

digit

radio64 kb/s 64 kb/s 64 kb/s 64 kb/s

LAPD

RR

BTSM

BSSAP

CM

MM

BSSAP

SCCP

MTP

SCCP

MTP LAYER 2

LAYER 1

LAYER 3


BSS protocol stacks


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SSCS

SSTM 3

SSTM 2

SSCS

SSTM 3

SSTM 2

SSGT

MAP

SSGT

MAP

SSCS

SSTM 3

SSTM 2

PCM TS

DTAP

SSCS

SSTM 3

SSTM 2

PCM TS

DTAP

LAPDLAPDm LAPD

SS (SMS)SS (SMS)

BSSMAP

MM

CC

BSSMAPRR

RR

RR' BTSMBTSM

LAPDm

(SMS)SSCC

MM

(Relay)

MS BTS BSC MSC / VLR NSS(ex. : HLR)

Um A bis A (D)1

2

3

(Relay

64 kbit/sor PCM TS

64 kbit/sor PCM TS PCM TS PCM TSPhycal

Layer

BSS protocol stacks (detailed)

PhycalLayer


1.336

Signaling on the A InterfaceUses #7 with Signaling Connection Control Part (SCCP) with a new Application Base Station Application Part (BSSAP). BSSAP is divided into Direct Transfer Application Part (DTAP) and Base Station Subsystem Management Application Part (BSSMAP)

DTAP

BSSMAP

SCCP

MTP 1-3

User Data

Layer 1-3

BSSAP



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BSSMAPContains the messages, which are exchanged between the BSC and the MSC and which are evaluated from the BSC. In fact all the messages, which are exchanged as RR (Radio Resource Management Services between the MSC, BSC and MS). Also control Information concerning the MSC and BSC.Example: Paging, HND_CMD, Reset

DTAPMessages which are exchanged between an NSS and an MS transparent. In this case, the BSC transfers the messages without evaluation transparent. Mainly Messages from Mobility Management(MM) and Call control (CC)



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Relationship between DTAP, CC, MM, BSSMAP, RR

MSBSS MSC

Call Control (CC) DTAP

Radio Resource (RR)BSSMAP


Back


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ANNEX 4

B8 Improvements summary

B8 Improvements summaryB8


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Location Services (LCS)SDDCH Dynamic allocationCounters Improvement

Inter PLMN HO3G to 2G HO (and 2G to 2G only)Dual band HO (New type: 32)LapD congestion counterQOS Followup

TCH assignment failure BSS PB now detailedHO Attempts for Fast Traffic added in type 110AMR counters added in type 110MS penetration (per speech version and channel type) was type 1 counters now available in type 110HO Causes: type 26 extended from 1 to 40 cellsDirected retry: type 29 becomes a standard (for PMC)

B8 Improvements summaryB8

7-qos b8 print

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